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authorDan Magenheimer <dan.magenheimer@oracle.com>2012-09-05 13:44:59 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-09-05 17:04:07 -0700
commitc857ce1659b058c087bce9874cb4eeb5adbf04c5 (patch)
tree5004bcc37e5e34ca78191a55684d738031cca341 /drivers/staging/ramster/zcache-main.c
parent3ddd31fa34485ccbe358432a632bec148be18127 (diff)
staging: ramster: remove old driver to prep for new base
[V2: rebased to apply to 20120905 staging-next, no other changes] To prep for moving the ramster codebase on top of the new redesigned zcache2 codebase, we remove ramster (as well as its contained diverged v1.1 version of zcache) entirely. Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/ramster/zcache-main.c')
-rw-r--r--drivers/staging/ramster/zcache-main.c3320
1 files changed, 0 insertions, 3320 deletions
diff --git a/drivers/staging/ramster/zcache-main.c b/drivers/staging/ramster/zcache-main.c
deleted file mode 100644
index d46764b5aab..00000000000
--- a/drivers/staging/ramster/zcache-main.c
+++ /dev/null
@@ -1,3320 +0,0 @@
-/*
- * zcache.c
- *
- * Copyright (c) 2010-2012, Dan Magenheimer, Oracle Corp.
- * Copyright (c) 2010,2011, Nitin Gupta
- *
- * Zcache provides an in-kernel "host implementation" for transcendent memory
- * and, thus indirectly, for cleancache and frontswap. Zcache includes two
- * page-accessible memory [1] interfaces, both utilizing lzo1x compression:
- * 1) "compression buddies" ("zbud") is used for ephemeral pages
- * 2) xvmalloc is used for persistent pages.
- * Xvmalloc (based on the TLSF allocator) has very low fragmentation
- * so maximizes space efficiency, while zbud allows pairs (and potentially,
- * in the future, more than a pair of) compressed pages to be closely linked
- * so that reclaiming can be done via the kernel's physical-page-oriented
- * "shrinker" interface.
- *
- * [1] For a definition of page-accessible memory (aka PAM), see:
- * http://marc.info/?l=linux-mm&m=127811271605009
- * RAMSTER TODO:
- * - handle remotifying of buddied pages (see zbud_remotify_zbpg)
- * - kernel boot params: nocleancache/nofrontswap don't always work?!?
- */
-
-#include <linux/module.h>
-#include <linux/cpu.h>
-#include <linux/highmem.h>
-#include <linux/list.h>
-#include <linux/lzo.h>
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/types.h>
-#include <linux/atomic.h>
-#include <linux/math64.h>
-#include "tmem.h"
-#include "zcache.h"
-#include "ramster.h"
-#include "cluster/tcp.h"
-
-#include "xvmalloc.h" /* temporary until change to zsmalloc */
-
-#define RAMSTER_TESTING
-
-#if (!defined(CONFIG_CLEANCACHE) && !defined(CONFIG_FRONTSWAP))
-#error "ramster is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP"
-#endif
-#ifdef CONFIG_CLEANCACHE
-#include <linux/cleancache.h>
-#endif
-#ifdef CONFIG_FRONTSWAP
-#include <linux/frontswap.h>
-#endif
-
-enum ramster_remotify_op {
- RAMSTER_REMOTIFY_EPH_PUT,
- RAMSTER_REMOTIFY_PERS_PUT,
- RAMSTER_REMOTIFY_FLUSH_PAGE,
- RAMSTER_REMOTIFY_FLUSH_OBJ,
- RAMSTER_INTRANSIT_PERS
-};
-
-struct ramster_remotify_hdr {
- enum ramster_remotify_op op;
- struct list_head list;
-};
-
-#define ZBH_SENTINEL 0x43214321
-#define ZBPG_SENTINEL 0xdeadbeef
-
-#define ZBUD_MAX_BUDS 2
-
-struct zbud_hdr {
- struct ramster_remotify_hdr rem_op;
- uint16_t client_id;
- uint16_t pool_id;
- struct tmem_oid oid;
- uint32_t index;
- uint16_t size; /* compressed size in bytes, zero means unused */
- DECL_SENTINEL
-};
-
-#define ZVH_SENTINEL 0x43214321
-static const int zv_max_page_size = (PAGE_SIZE / 8) * 7;
-
-struct zv_hdr {
- struct ramster_remotify_hdr rem_op;
- uint16_t client_id;
- uint16_t pool_id;
- struct tmem_oid oid;
- uint32_t index;
- DECL_SENTINEL
-};
-
-struct flushlist_node {
- struct ramster_remotify_hdr rem_op;
- struct tmem_xhandle xh;
-};
-
-union {
- struct ramster_remotify_hdr rem_op;
- struct zv_hdr zv;
- struct zbud_hdr zbud;
- struct flushlist_node flist;
-} remotify_list_node;
-
-static LIST_HEAD(zcache_rem_op_list);
-static DEFINE_SPINLOCK(zcache_rem_op_list_lock);
-
-#if 0
-/* this is more aggressive but may cause other problems? */
-#define ZCACHE_GFP_MASK (GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN)
-#else
-#define ZCACHE_GFP_MASK \
- (__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC)
-#endif
-
-#define MAX_POOLS_PER_CLIENT 16
-
-#define MAX_CLIENTS 16
-#define LOCAL_CLIENT ((uint16_t)-1)
-
-MODULE_LICENSE("GPL");
-
-struct zcache_client {
- struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT];
- struct xv_pool *xvpool;
- bool allocated;
- atomic_t refcount;
-};
-
-static struct zcache_client zcache_host;
-static struct zcache_client zcache_clients[MAX_CLIENTS];
-
-static inline uint16_t get_client_id_from_client(struct zcache_client *cli)
-{
- BUG_ON(cli == NULL);
- if (cli == &zcache_host)
- return LOCAL_CLIENT;
- return cli - &zcache_clients[0];
-}
-
-static inline bool is_local_client(struct zcache_client *cli)
-{
- return cli == &zcache_host;
-}
-
-/**********
- * Compression buddies ("zbud") provides for packing two (or, possibly
- * in the future, more) compressed ephemeral pages into a single "raw"
- * (physical) page and tracking them with data structures so that
- * the raw pages can be easily reclaimed.
- *
- * A zbud page ("zbpg") is an aligned page containing a list_head,
- * a lock, and two "zbud headers". The remainder of the physical
- * page is divided up into aligned 64-byte "chunks" which contain
- * the compressed data for zero, one, or two zbuds. Each zbpg
- * resides on: (1) an "unused list" if it has no zbuds; (2) a
- * "buddied" list if it is fully populated with two zbuds; or
- * (3) one of PAGE_SIZE/64 "unbuddied" lists indexed by how many chunks
- * the one unbuddied zbud uses. The data inside a zbpg cannot be
- * read or written unless the zbpg's lock is held.
- */
-
-struct zbud_page {
- struct list_head bud_list;
- spinlock_t lock;
- struct zbud_hdr buddy[ZBUD_MAX_BUDS];
- DECL_SENTINEL
- /* followed by NUM_CHUNK aligned CHUNK_SIZE-byte chunks */
-};
-
-#define CHUNK_SHIFT 6
-#define CHUNK_SIZE (1 << CHUNK_SHIFT)
-#define CHUNK_MASK (~(CHUNK_SIZE-1))
-#define NCHUNKS (((PAGE_SIZE - sizeof(struct zbud_page)) & \
- CHUNK_MASK) >> CHUNK_SHIFT)
-#define MAX_CHUNK (NCHUNKS-1)
-
-static struct {
- struct list_head list;
- unsigned count;
-} zbud_unbuddied[NCHUNKS];
-/* list N contains pages with N chunks USED and NCHUNKS-N unused */
-/* element 0 is never used but optimizing that isn't worth it */
-static unsigned long zbud_cumul_chunk_counts[NCHUNKS];
-
-struct list_head zbud_buddied_list;
-static unsigned long zcache_zbud_buddied_count;
-
-/* protects the buddied list and all unbuddied lists */
-static DEFINE_SPINLOCK(zbud_budlists_spinlock);
-
-static atomic_t zcache_zbud_curr_raw_pages;
-static atomic_t zcache_zbud_curr_zpages;
-static unsigned long zcache_zbud_curr_zbytes;
-static unsigned long zcache_zbud_cumul_zpages;
-static unsigned long zcache_zbud_cumul_zbytes;
-static unsigned long zcache_compress_poor;
-static unsigned long zcache_policy_percent_exceeded;
-static unsigned long zcache_mean_compress_poor;
-
-/*
- * RAMster counters
- * - Remote pages are pages with a local pampd but the data is remote
- * - Foreign pages are pages stored locally but belonging to another node
- */
-static atomic_t ramster_remote_pers_pages = ATOMIC_INIT(0);
-static unsigned long ramster_pers_remotify_enable;
-static unsigned long ramster_eph_remotify_enable;
-static unsigned long ramster_eph_pages_remoted;
-static unsigned long ramster_eph_pages_remote_failed;
-static unsigned long ramster_pers_pages_remoted;
-static unsigned long ramster_pers_pages_remote_failed;
-static unsigned long ramster_pers_pages_remote_nomem;
-static unsigned long ramster_remote_objects_flushed;
-static unsigned long ramster_remote_object_flushes_failed;
-static unsigned long ramster_remote_pages_flushed;
-static unsigned long ramster_remote_page_flushes_failed;
-static unsigned long ramster_remote_eph_pages_succ_get;
-static unsigned long ramster_remote_pers_pages_succ_get;
-static unsigned long ramster_remote_eph_pages_unsucc_get;
-static unsigned long ramster_remote_pers_pages_unsucc_get;
-static atomic_t ramster_curr_flnode_count = ATOMIC_INIT(0);
-static unsigned long ramster_curr_flnode_count_max;
-static atomic_t ramster_foreign_eph_pampd_count = ATOMIC_INIT(0);
-static unsigned long ramster_foreign_eph_pampd_count_max;
-static atomic_t ramster_foreign_pers_pampd_count = ATOMIC_INIT(0);
-static unsigned long ramster_foreign_pers_pampd_count_max;
-
-/* forward references */
-static void *zcache_get_free_page(void);
-static void zcache_free_page(void *p);
-
-/*
- * zbud helper functions
- */
-
-static inline unsigned zbud_max_buddy_size(void)
-{
- return MAX_CHUNK << CHUNK_SHIFT;
-}
-
-static inline unsigned zbud_size_to_chunks(unsigned size)
-{
- BUG_ON(size == 0 || size > zbud_max_buddy_size());
- return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT;
-}
-
-static inline int zbud_budnum(struct zbud_hdr *zh)
-{
- unsigned offset = (unsigned long)zh & (PAGE_SIZE - 1);
- struct zbud_page *zbpg = NULL;
- unsigned budnum = -1U;
- int i;
-
- for (i = 0; i < ZBUD_MAX_BUDS; i++)
- if (offset == offsetof(typeof(*zbpg), buddy[i])) {
- budnum = i;
- break;
- }
- BUG_ON(budnum == -1U);
- return budnum;
-}
-
-static char *zbud_data(struct zbud_hdr *zh, unsigned size)
-{
- struct zbud_page *zbpg;
- char *p;
- unsigned budnum;
-
- ASSERT_SENTINEL(zh, ZBH);
- budnum = zbud_budnum(zh);
- BUG_ON(size == 0 || size > zbud_max_buddy_size());
- zbpg = container_of(zh, struct zbud_page, buddy[budnum]);
- ASSERT_SPINLOCK(&zbpg->lock);
- p = (char *)zbpg;
- if (budnum == 0)
- p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) &
- CHUNK_MASK);
- else if (budnum == 1)
- p += PAGE_SIZE - ((size + CHUNK_SIZE - 1) & CHUNK_MASK);
- return p;
-}
-
-static void zbud_copy_from_pampd(char *data, size_t *size, struct zbud_hdr *zh)
-{
- struct zbud_page *zbpg;
- char *p;
- unsigned budnum;
-
- ASSERT_SENTINEL(zh, ZBH);
- budnum = zbud_budnum(zh);
- zbpg = container_of(zh, struct zbud_page, buddy[budnum]);
- spin_lock(&zbpg->lock);
- BUG_ON(zh->size > *size);
- p = (char *)zbpg;
- if (budnum == 0)
- p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) &
- CHUNK_MASK);
- else if (budnum == 1)
- p += PAGE_SIZE - ((zh->size + CHUNK_SIZE - 1) & CHUNK_MASK);
- /* client should be filled in by caller */
- memcpy(data, p, zh->size);
- *size = zh->size;
- spin_unlock(&zbpg->lock);
-}
-
-/*
- * zbud raw page management
- */
-
-static struct zbud_page *zbud_alloc_raw_page(void)
-{
- struct zbud_page *zbpg = NULL;
- struct zbud_hdr *zh0, *zh1;
- zbpg = zcache_get_free_page();
- if (likely(zbpg != NULL)) {
- INIT_LIST_HEAD(&zbpg->bud_list);
- zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1];
- spin_lock_init(&zbpg->lock);
- atomic_inc(&zcache_zbud_curr_raw_pages);
- INIT_LIST_HEAD(&zbpg->bud_list);
- SET_SENTINEL(zbpg, ZBPG);
- zh0->size = 0; zh1->size = 0;
- tmem_oid_set_invalid(&zh0->oid);
- tmem_oid_set_invalid(&zh1->oid);
- }
- return zbpg;
-}
-
-static void zbud_free_raw_page(struct zbud_page *zbpg)
-{
- struct zbud_hdr *zh0 = &zbpg->buddy[0], *zh1 = &zbpg->buddy[1];
-
- ASSERT_SENTINEL(zbpg, ZBPG);
- BUG_ON(!list_empty(&zbpg->bud_list));
- ASSERT_SPINLOCK(&zbpg->lock);
- BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid));
- BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid));
- INVERT_SENTINEL(zbpg, ZBPG);
- spin_unlock(&zbpg->lock);
- atomic_dec(&zcache_zbud_curr_raw_pages);
- zcache_free_page(zbpg);
-}
-
-/*
- * core zbud handling routines
- */
-
-static unsigned zbud_free(struct zbud_hdr *zh)
-{
- unsigned size;
-
- ASSERT_SENTINEL(zh, ZBH);
- BUG_ON(!tmem_oid_valid(&zh->oid));
- size = zh->size;
- BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size());
- zh->size = 0;
- tmem_oid_set_invalid(&zh->oid);
- INVERT_SENTINEL(zh, ZBH);
- zcache_zbud_curr_zbytes -= size;
- atomic_dec(&zcache_zbud_curr_zpages);
- return size;
-}
-
-static void zbud_free_and_delist(struct zbud_hdr *zh)
-{
- unsigned chunks;
- struct zbud_hdr *zh_other;
- unsigned budnum = zbud_budnum(zh), size;
- struct zbud_page *zbpg =
- container_of(zh, struct zbud_page, buddy[budnum]);
-
- /* FIXME, should be BUG_ON, pool destruction path doesn't disable
- * interrupts tmem_destroy_pool()->tmem_pampd_destroy_all_in_obj()->
- * tmem_objnode_node_destroy()-> zcache_pampd_free() */
- WARN_ON(!irqs_disabled());
- spin_lock(&zbpg->lock);
- if (list_empty(&zbpg->bud_list)) {
- /* ignore zombie page... see zbud_evict_pages() */
- spin_unlock(&zbpg->lock);
- return;
- }
- size = zbud_free(zh);
- ASSERT_SPINLOCK(&zbpg->lock);
- zh_other = &zbpg->buddy[(budnum == 0) ? 1 : 0];
- if (zh_other->size == 0) { /* was unbuddied: unlist and free */
- chunks = zbud_size_to_chunks(size) ;
- spin_lock(&zbud_budlists_spinlock);
- BUG_ON(list_empty(&zbud_unbuddied[chunks].list));
- list_del_init(&zbpg->bud_list);
- zbud_unbuddied[chunks].count--;
- spin_unlock(&zbud_budlists_spinlock);
- zbud_free_raw_page(zbpg);
- } else { /* was buddied: move remaining buddy to unbuddied list */
- chunks = zbud_size_to_chunks(zh_other->size) ;
- spin_lock(&zbud_budlists_spinlock);
- list_del_init(&zbpg->bud_list);
- zcache_zbud_buddied_count--;
- list_add_tail(&zbpg->bud_list, &zbud_unbuddied[chunks].list);
- zbud_unbuddied[chunks].count++;
- spin_unlock(&zbud_budlists_spinlock);
- spin_unlock(&zbpg->lock);
- }
-}
-
-static struct zbud_hdr *zbud_create(uint16_t client_id, uint16_t pool_id,
- struct tmem_oid *oid,
- uint32_t index, struct page *page,
- void *cdata, unsigned size)
-{
- struct zbud_hdr *zh0, *zh1, *zh = NULL;
- struct zbud_page *zbpg = NULL, *ztmp;
- unsigned nchunks;
- char *to;
- int i, found_good_buddy = 0;
-
- nchunks = zbud_size_to_chunks(size) ;
- for (i = MAX_CHUNK - nchunks + 1; i > 0; i--) {
- spin_lock(&zbud_budlists_spinlock);
- if (!list_empty(&zbud_unbuddied[i].list)) {
- list_for_each_entry_safe(zbpg, ztmp,
- &zbud_unbuddied[i].list, bud_list) {
- if (spin_trylock(&zbpg->lock)) {
- found_good_buddy = i;
- goto found_unbuddied;
- }
- }
- }
- spin_unlock(&zbud_budlists_spinlock);
- }
- /* didn't find a good buddy, try allocating a new page */
- zbpg = zbud_alloc_raw_page();
- if (unlikely(zbpg == NULL))
- goto out;
- /* ok, have a page, now compress the data before taking locks */
- spin_lock(&zbud_budlists_spinlock);
- spin_lock(&zbpg->lock);
- list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list);
- zbud_unbuddied[nchunks].count++;
- zh = &zbpg->buddy[0];
- goto init_zh;
-
-found_unbuddied:
- ASSERT_SPINLOCK(&zbpg->lock);
- zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1];
- BUG_ON(!((zh0->size == 0) ^ (zh1->size == 0)));
- if (zh0->size != 0) { /* buddy0 in use, buddy1 is vacant */
- ASSERT_SENTINEL(zh0, ZBH);
- zh = zh1;
- } else if (zh1->size != 0) { /* buddy1 in use, buddy0 is vacant */
- ASSERT_SENTINEL(zh1, ZBH);
- zh = zh0;
- } else
- BUG();
- list_del_init(&zbpg->bud_list);
- zbud_unbuddied[found_good_buddy].count--;
- list_add_tail(&zbpg->bud_list, &zbud_buddied_list);
- zcache_zbud_buddied_count++;
-
-init_zh:
- SET_SENTINEL(zh, ZBH);
- zh->size = size;
- zh->index = index;
- zh->oid = *oid;
- zh->pool_id = pool_id;
- zh->client_id = client_id;
- to = zbud_data(zh, size);
- memcpy(to, cdata, size);
- spin_unlock(&zbpg->lock);
- spin_unlock(&zbud_budlists_spinlock);
- zbud_cumul_chunk_counts[nchunks]++;
- atomic_inc(&zcache_zbud_curr_zpages);
- zcache_zbud_cumul_zpages++;
- zcache_zbud_curr_zbytes += size;
- zcache_zbud_cumul_zbytes += size;
-out:
- return zh;
-}
-
-static int zbud_decompress(struct page *page, struct zbud_hdr *zh)
-{
- struct zbud_page *zbpg;
- unsigned budnum = zbud_budnum(zh);
- size_t out_len = PAGE_SIZE;
- char *to_va, *from_va;
- unsigned size;
- int ret = 0;
-
- zbpg = container_of(zh, struct zbud_page, buddy[budnum]);
- spin_lock(&zbpg->lock);
- if (list_empty(&zbpg->bud_list)) {
- /* ignore zombie page... see zbud_evict_pages() */
- ret = -EINVAL;
- goto out;
- }
- ASSERT_SENTINEL(zh, ZBH);
- BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size());
- to_va = kmap_atomic(page);
- size = zh->size;
- from_va = zbud_data(zh, size);
- ret = lzo1x_decompress_safe(from_va, size, to_va, &out_len);
- BUG_ON(ret != LZO_E_OK);
- BUG_ON(out_len != PAGE_SIZE);
- kunmap_atomic(to_va);
-out:
- spin_unlock(&zbpg->lock);
- return ret;
-}
-
-/*
- * The following routines handle shrinking of ephemeral pages by evicting
- * pages "least valuable" first.
- */
-
-static unsigned long zcache_evicted_raw_pages;
-static unsigned long zcache_evicted_buddied_pages;
-static unsigned long zcache_evicted_unbuddied_pages;
-
-static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id,
- uint16_t poolid);
-static void zcache_put_pool(struct tmem_pool *pool);
-
-/*
- * Flush and free all zbuds in a zbpg, then free the pageframe
- */
-static void zbud_evict_zbpg(struct zbud_page *zbpg)
-{
- struct zbud_hdr *zh;
- int i, j;
- uint32_t pool_id[ZBUD_MAX_BUDS], client_id[ZBUD_MAX_BUDS];
- uint32_t index[ZBUD_MAX_BUDS];
- struct tmem_oid oid[ZBUD_MAX_BUDS];
- struct tmem_pool *pool;
- unsigned long flags;
-
- ASSERT_SPINLOCK(&zbpg->lock);
- for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) {
- zh = &zbpg->buddy[i];
- if (zh->size) {
- client_id[j] = zh->client_id;
- pool_id[j] = zh->pool_id;
- oid[j] = zh->oid;
- index[j] = zh->index;
- j++;
- }
- }
- spin_unlock(&zbpg->lock);
- for (i = 0; i < j; i++) {
- pool = zcache_get_pool_by_id(client_id[i], pool_id[i]);
- BUG_ON(pool == NULL);
- local_irq_save(flags);
- /* these flushes should dispose of any local storage */
- tmem_flush_page(pool, &oid[i], index[i]);
- local_irq_restore(flags);
- zcache_put_pool(pool);
- }
-}
-
-/*
- * Free nr pages. This code is funky because we want to hold the locks
- * protecting various lists for as short a time as possible, and in some
- * circumstances the list may change asynchronously when the list lock is
- * not held. In some cases we also trylock not only to avoid waiting on a
- * page in use by another cpu, but also to avoid potential deadlock due to
- * lock inversion.
- */
-static void zbud_evict_pages(int nr)
-{
- struct zbud_page *zbpg;
- int i, newly_unused_pages = 0;
-
-
- /* now try freeing unbuddied pages, starting with least space avail */
- for (i = 0; i < MAX_CHUNK; i++) {
-retry_unbud_list_i:
- spin_lock_bh(&zbud_budlists_spinlock);
- if (list_empty(&zbud_unbuddied[i].list)) {
- spin_unlock_bh(&zbud_budlists_spinlock);
- continue;
- }
- list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) {
- if (unlikely(!spin_trylock(&zbpg->lock)))
- continue;
- zbud_unbuddied[i].count--;
- spin_unlock(&zbud_budlists_spinlock);
- zcache_evicted_unbuddied_pages++;
- /* want budlists unlocked when doing zbpg eviction */
- zbud_evict_zbpg(zbpg);
- newly_unused_pages++;
- local_bh_enable();
- if (--nr <= 0)
- goto evict_unused;
- goto retry_unbud_list_i;
- }
- spin_unlock_bh(&zbud_budlists_spinlock);
- }
-
- /* as a last resort, free buddied pages */
-retry_bud_list:
- spin_lock_bh(&zbud_budlists_spinlock);
- if (list_empty(&zbud_buddied_list)) {
- spin_unlock_bh(&zbud_budlists_spinlock);
- goto evict_unused;
- }
- list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) {
- if (unlikely(!spin_trylock(&zbpg->lock)))
- continue;
- zcache_zbud_buddied_count--;
- spin_unlock(&zbud_budlists_spinlock);
- zcache_evicted_buddied_pages++;
- /* want budlists unlocked when doing zbpg eviction */
- zbud_evict_zbpg(zbpg);
- newly_unused_pages++;
- local_bh_enable();
- if (--nr <= 0)
- goto evict_unused;
- goto retry_bud_list;
- }
- spin_unlock_bh(&zbud_budlists_spinlock);
-
-evict_unused:
- return;
-}
-
-static DEFINE_PER_CPU(unsigned char *, zcache_remoteputmem);
-
-static int zbud_remotify_zbud(struct tmem_xhandle *xh, char *data,
- size_t size)
-{
- struct tmem_pool *pool;
- int i, remotenode, ret = -1;
- unsigned char cksum, *p;
- unsigned long flags;
-
- for (p = data, cksum = 0, i = 0; i < size; i++)
- cksum += *p;
- ret = ramster_remote_put(xh, data, size, true, &remotenode);
- if (ret == 0) {
- /* data was successfully remoted so change the local version
- * to point to the remote node where it landed */
- pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh->pool_id);
- BUG_ON(pool == NULL);
- local_irq_save(flags);
- /* tmem_replace will also free up any local space */
- (void)tmem_replace(pool, &xh->oid, xh->index,
- pampd_make_remote(remotenode, size, cksum));
- local_irq_restore(flags);
- zcache_put_pool(pool);
- ramster_eph_pages_remoted++;
- ret = 0;
- } else
- ramster_eph_pages_remote_failed++;
- return ret;
-}
-
-static int zbud_remotify_zbpg(struct zbud_page *zbpg)
-{
- struct zbud_hdr *zh1, *zh2 = NULL;
- struct tmem_xhandle xh1, xh2 = { 0 };
- char *data1 = NULL, *data2 = NULL;
- size_t size1 = 0, size2 = 0;
- int ret = 0;
- unsigned char *tmpmem = __get_cpu_var(zcache_remoteputmem);
-
- ASSERT_SPINLOCK(&zbpg->lock);
- if (zbpg->buddy[0].size == 0)
- zh1 = &zbpg->buddy[1];
- else if (zbpg->buddy[1].size == 0)
- zh1 = &zbpg->buddy[0];
- else {
- zh1 = &zbpg->buddy[0];
- zh2 = &zbpg->buddy[1];
- }
- /* don't remotify pages that are already remotified */
- if (zh1->client_id != LOCAL_CLIENT)
- zh1 = NULL;
- if ((zh2 != NULL) && (zh2->client_id != LOCAL_CLIENT))
- zh2 = NULL;
-
- /* copy the data and metadata so can release lock */
- if (zh1 != NULL) {
- xh1.client_id = zh1->client_id;
- xh1.pool_id = zh1->pool_id;
- xh1.oid = zh1->oid;
- xh1.index = zh1->index;
- size1 = zh1->size;
- data1 = zbud_data(zh1, size1);
- memcpy(tmpmem, zbud_data(zh1, size1), size1);
- data1 = tmpmem;
- tmpmem += size1;
- }
- if (zh2 != NULL) {
- xh2.client_id = zh2->client_id;
- xh2.pool_id = zh2->pool_id;
- xh2.oid = zh2->oid;
- xh2.index = zh2->index;
- size2 = zh2->size;
- memcpy(tmpmem, zbud_data(zh2, size2), size2);
- data2 = tmpmem;
- }
- spin_unlock(&zbpg->lock);
- preempt_enable();
-
- /* OK, no locks held anymore, remotify one or both zbuds */
- if (zh1 != NULL)
- ret = zbud_remotify_zbud(&xh1, data1, size1);
- if (zh2 != NULL)
- ret |= zbud_remotify_zbud(&xh2, data2, size2);
- return ret;
-}
-
-void zbud_remotify_pages(int nr)
-{
- struct zbud_page *zbpg;
- int i, ret;
-
- /*
- * for now just try remotifying unbuddied pages, starting with
- * least space avail
- */
- for (i = 0; i < MAX_CHUNK; i++) {
-retry_unbud_list_i:
- preempt_disable(); /* enable in zbud_remotify_zbpg */
- spin_lock_bh(&zbud_budlists_spinlock);
- if (list_empty(&zbud_unbuddied[i].list)) {
- spin_unlock_bh(&zbud_budlists_spinlock);
- preempt_enable();
- continue; /* next i in for loop */
- }
- list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) {
- if (unlikely(!spin_trylock(&zbpg->lock)))
- continue; /* next list_for_each_entry */
- zbud_unbuddied[i].count--;
- /* want budlists unlocked when doing zbpg remotify */
- spin_unlock_bh(&zbud_budlists_spinlock);
- ret = zbud_remotify_zbpg(zbpg);
- /* preemption is re-enabled in zbud_remotify_zbpg */
- if (ret == 0) {
- if (--nr <= 0)
- goto out;
- goto retry_unbud_list_i;
- }
- /* if fail to remotify any page, quit */
- pr_err("TESTING zbud_remotify_pages failed on page,"
- " trying to re-add\n");
- spin_lock_bh(&zbud_budlists_spinlock);
- spin_lock(&zbpg->lock);
- list_add_tail(&zbpg->bud_list, &zbud_unbuddied[i].list);
- zbud_unbuddied[i].count++;
- spin_unlock(&zbpg->lock);
- spin_unlock_bh(&zbud_budlists_spinlock);
- pr_err("TESTING zbud_remotify_pages failed on page,"
- " finished re-add\n");
- goto out;
- }
- spin_unlock_bh(&zbud_budlists_spinlock);
- preempt_enable();
- }
-
-next_buddied_zbpg:
- preempt_disable(); /* enable in zbud_remotify_zbpg */
- spin_lock_bh(&zbud_budlists_spinlock);
- if (list_empty(&zbud_buddied_list))
- goto unlock_out;
- list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) {
- if (unlikely(!spin_trylock(&zbpg->lock)))
- continue; /* next list_for_each_entry */
- zcache_zbud_buddied_count--;
- /* want budlists unlocked when doing zbpg remotify */
- spin_unlock_bh(&zbud_budlists_spinlock);
- ret = zbud_remotify_zbpg(zbpg);
- /* preemption is re-enabled in zbud_remotify_zbpg */
- if (ret == 0) {
- if (--nr <= 0)
- goto out;
- goto next_buddied_zbpg;
- }
- /* if fail to remotify any page, quit */
- pr_err("TESTING zbud_remotify_pages failed on BUDDIED page,"
- " trying to re-add\n");
- spin_lock_bh(&zbud_budlists_spinlock);
- spin_lock(&zbpg->lock);
- list_add_tail(&zbpg->bud_list, &zbud_buddied_list);
- zcache_zbud_buddied_count++;
- spin_unlock(&zbpg->lock);
- spin_unlock_bh(&zbud_budlists_spinlock);
- pr_err("TESTING zbud_remotify_pages failed on BUDDIED page,"
- " finished re-add\n");
- goto out;
- }
-unlock_out:
- spin_unlock_bh(&zbud_budlists_spinlock);
- preempt_enable();
-out:
- return;
-}
-
-/* the "flush list" asynchronously collects pages to remotely flush */
-#define FLUSH_ENTIRE_OBJECT ((uint32_t)-1)
-static void ramster_flnode_free(struct flushlist_node *,
- struct tmem_pool *);
-
-static void zcache_remote_flush_page(struct flushlist_node *flnode)
-{
- struct tmem_xhandle *xh;
- int remotenode, ret;
-
- preempt_disable();
- xh = &flnode->xh;
- remotenode = flnode->xh.client_id;
- ret = ramster_remote_flush(xh, remotenode);
- if (ret >= 0)
- ramster_remote_pages_flushed++;
- else
- ramster_remote_page_flushes_failed++;
- preempt_enable_no_resched();
- ramster_flnode_free(flnode, NULL);
-}
-
-static void zcache_remote_flush_object(struct flushlist_node *flnode)
-{
- struct tmem_xhandle *xh;
- int remotenode, ret;
-
- preempt_disable();
- xh = &flnode->xh;
- remotenode = flnode->xh.client_id;
- ret = ramster_remote_flush_object(xh, remotenode);
- if (ret >= 0)
- ramster_remote_objects_flushed++;
- else
- ramster_remote_object_flushes_failed++;
- preempt_enable_no_resched();
- ramster_flnode_free(flnode, NULL);
-}
-
-static void zcache_remote_eph_put(struct zbud_hdr *zbud)
-{
- /* FIXME */
-}
-
-static void zcache_remote_pers_put(struct zv_hdr *zv)
-{
- struct tmem_xhandle xh;
- uint16_t size;
- bool ephemeral;
- int remotenode, ret = -1;
- char *data;
- struct tmem_pool *pool;
- unsigned long flags;
- unsigned char cksum;
- char *p;
- int i;
- unsigned char *tmpmem = __get_cpu_var(zcache_remoteputmem);
-
- ASSERT_SENTINEL(zv, ZVH);
- BUG_ON(zv->client_id != LOCAL_CLIENT);
- local_bh_disable();
- xh.client_id = zv->client_id;
- xh.pool_id = zv->pool_id;
- xh.oid = zv->oid;
- xh.index = zv->index;
- size = xv_get_object_size(zv) - sizeof(*zv);
- BUG_ON(size == 0 || size > zv_max_page_size);
- data = (char *)zv + sizeof(*zv);
- for (p = data, cksum = 0, i = 0; i < size; i++)
- cksum += *p;
- memcpy(tmpmem, data, size);
- data = tmpmem;
- pool = zcache_get_pool_by_id(zv->client_id, zv->pool_id);
- ephemeral = is_ephemeral(pool);
- zcache_put_pool(pool);
- /* now OK to release lock set in caller */
- spin_unlock(&zcache_rem_op_list_lock);
- local_bh_enable();
- preempt_disable();
- ret = ramster_remote_put(&xh, data, size, ephemeral, &remotenode);
- preempt_enable_no_resched();
- if (ret != 0) {
- /*
- * This is some form of a memory leak... if the remote put
- * fails, there will never be another attempt to remotify
- * this page. But since we've dropped the zv pointer,
- * the page may have been freed or the data replaced
- * so we can't just "put it back" in the remote op list.
- * Even if we could, not sure where to put it in the list
- * because there may be flushes that must be strictly
- * ordered vs the put. So leave this as a FIXME for now.
- * But count them so we know if it becomes a problem.
- */
- ramster_pers_pages_remote_failed++;
- goto out;
- } else
- atomic_inc(&ramster_remote_pers_pages);
- ramster_pers_pages_remoted++;
- /*
- * data was successfully remoted so change the local version to
- * point to the remote node where it landed
- */
- local_bh_disable();
- pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh.pool_id);
- local_irq_save(flags);
- (void)tmem_replace(pool, &xh.oid, xh.index,
- pampd_make_remote(remotenode, size, cksum));
- local_irq_restore(flags);
- zcache_put_pool(pool);
- local_bh_enable();
-out:
- return;
-}
-
-static void zcache_do_remotify_ops(int nr)
-{
- struct ramster_remotify_hdr *rem_op;
- union remotify_list_node *u;
-
- while (1) {
- if (!nr)
- goto out;
- spin_lock(&zcache_rem_op_list_lock);
- if (list_empty(&zcache_rem_op_list)) {
- spin_unlock(&zcache_rem_op_list_lock);
- goto out;
- }
- rem_op = list_first_entry(&zcache_rem_op_list,
- struct ramster_remotify_hdr, list);
- list_del_init(&rem_op->list);
- if (rem_op->op != RAMSTER_REMOTIFY_PERS_PUT)
- spin_unlock(&zcache_rem_op_list_lock);
- u = (union remotify_list_node *)rem_op;
- switch (rem_op->op) {
- case RAMSTER_REMOTIFY_EPH_PUT:
-BUG();
- zcache_remote_eph_put((struct zbud_hdr *)rem_op);
- break;
- case RAMSTER_REMOTIFY_PERS_PUT:
- zcache_remote_pers_put((struct zv_hdr *)rem_op);
- break;
- case RAMSTER_REMOTIFY_FLUSH_PAGE:
- zcache_remote_flush_page((struct flushlist_node *)u);
- break;
- case RAMSTER_REMOTIFY_FLUSH_OBJ:
- zcache_remote_flush_object((struct flushlist_node *)u);
- break;
- default:
- BUG();
- }
- }
-out:
- return;
-}
-
-/*
- * Communicate interface revision with userspace
- */
-#include "cluster/ramster_nodemanager.h"
-static unsigned long ramster_interface_revision = R2NM_API_VERSION;
-
-/*
- * For now, just push over a few pages every few seconds to
- * ensure that it basically works
- */
-static struct workqueue_struct *ramster_remotify_workqueue;
-static void ramster_remotify_process(struct work_struct *work);
-static DECLARE_DELAYED_WORK(ramster_remotify_worker,
- ramster_remotify_process);
-
-static void ramster_remotify_queue_delayed_work(unsigned long delay)
-{
- if (!queue_delayed_work(ramster_remotify_workqueue,
- &ramster_remotify_worker, delay))
- pr_err("ramster_remotify: bad workqueue\n");
-}
-
-
-static int use_frontswap;
-static int use_cleancache;
-static int ramster_remote_target_nodenum = -1;
-static void ramster_remotify_process(struct work_struct *work)
-{
- static bool remotify_in_progress;
-
- BUG_ON(irqs_disabled());
- if (remotify_in_progress)
- ramster_remotify_queue_delayed_work(HZ);
- else if (ramster_remote_target_nodenum != -1) {
- remotify_in_progress = true;
-#ifdef CONFIG_CLEANCACHE
- if (use_cleancache && ramster_eph_remotify_enable)
- zbud_remotify_pages(5000); /* FIXME is this a good number? */
-#endif
-#ifdef CONFIG_FRONTSWAP
- if (use_frontswap && ramster_pers_remotify_enable)
- zcache_do_remotify_ops(500); /* FIXME is this a good number? */
-#endif
- remotify_in_progress = false;
- ramster_remotify_queue_delayed_work(HZ);
- }
-}
-
-static void ramster_remotify_init(void)
-{
- unsigned long n = 60UL;
- ramster_remotify_workqueue =
- create_singlethread_workqueue("ramster_remotify");
- ramster_remotify_queue_delayed_work(n * HZ);
-}
-
-
-static void zbud_init(void)
-{
- int i;
-
- INIT_LIST_HEAD(&zbud_buddied_list);
- zcache_zbud_buddied_count = 0;
- for (i = 0; i < NCHUNKS; i++) {
- INIT_LIST_HEAD(&zbud_unbuddied[i].list);
- zbud_unbuddied[i].count = 0;
- }
-}
-
-#ifdef CONFIG_SYSFS
-/*
- * These sysfs routines show a nice distribution of how many zbpg's are
- * currently (and have ever been placed) in each unbuddied list. It's fun
- * to watch but can probably go away before final merge.
- */
-static int zbud_show_unbuddied_list_counts(char *buf)
-{
- int i;
- char *p = buf;
-
- for (i = 0; i < NCHUNKS; i++)
- p += sprintf(p, "%u ", zbud_unbuddied[i].count);
- return p - buf;
-}
-
-static int zbud_show_cumul_chunk_counts(char *buf)
-{
- unsigned long i, chunks = 0, total_chunks = 0, sum_total_chunks = 0;
- unsigned long total_chunks_lte_21 = 0, total_chunks_lte_32 = 0;
- unsigned long total_chunks_lte_42 = 0;
- char *p = buf;
-
- for (i = 0; i < NCHUNKS; i++) {
- p += sprintf(p, "%lu ", zbud_cumul_chunk_counts[i]);
- chunks += zbud_cumul_chunk_counts[i];
- total_chunks += zbud_cumul_chunk_counts[i];
- sum_total_chunks += i * zbud_cumul_chunk_counts[i];
- if (i == 21)
- total_chunks_lte_21 = total_chunks;
- if (i == 32)
- total_chunks_lte_32 = total_chunks;
- if (i == 42)
- total_chunks_lte_42 = total_chunks;
- }
- p += sprintf(p, "<=21:%lu <=32:%lu <=42:%lu, mean:%lu\n",
- total_chunks_lte_21, total_chunks_lte_32, total_chunks_lte_42,
- chunks == 0 ? 0 : sum_total_chunks / chunks);
- return p - buf;
-}
-#endif
-
-/**********
- * This "zv" PAM implementation combines the TLSF-based xvMalloc
- * with lzo1x compression to maximize the amount of data that can
- * be packed into a physical page.
- *
- * Zv represents a PAM page with the index and object (plus a "size" value
- * necessary for decompression) immediately preceding the compressed data.
- */
-
-/* rudimentary policy limits */
-/* total number of persistent pages may not exceed this percentage */
-static unsigned int zv_page_count_policy_percent = 75;
-/*
- * byte count defining poor compression; pages with greater zsize will be
- * rejected
- */
-static unsigned int zv_max_zsize = (PAGE_SIZE / 8) * 7;
-/*
- * byte count defining poor *mean* compression; pages with greater zsize
- * will be rejected until sufficient better-compressed pages are accepted
- * driving the mean below this threshold
- */
-static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5;
-
-static atomic_t zv_curr_dist_counts[NCHUNKS];
-static atomic_t zv_cumul_dist_counts[NCHUNKS];
-
-
-static struct zv_hdr *zv_create(struct zcache_client *cli, uint32_t pool_id,
- struct tmem_oid *oid, uint32_t index,
- void *cdata, unsigned clen)
-{
- struct page *page;
- struct zv_hdr *zv = NULL;
- uint32_t offset;
- int alloc_size = clen + sizeof(struct zv_hdr);
- int chunks = (alloc_size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT;
- int ret;
-
- BUG_ON(!irqs_disabled());
- BUG_ON(chunks >= NCHUNKS);
- ret = xv_malloc(cli->xvpool, clen + sizeof(struct zv_hdr),
- &page, &offset, ZCACHE_GFP_MASK);
- if (unlikely(ret))
- goto out;
- atomic_inc(&zv_curr_dist_counts[chunks]);
- atomic_inc(&zv_cumul_dist_counts[chunks]);
- zv = kmap_atomic(page) + offset;
- zv->index = index;
- zv->oid = *oid;
- zv->pool_id = pool_id;
- SET_SENTINEL(zv, ZVH);
- INIT_LIST_HEAD(&zv->rem_op.list);
- zv->client_id = get_client_id_from_client(cli);
- zv->rem_op.op = RAMSTER_REMOTIFY_PERS_PUT;
- if (zv->client_id == LOCAL_CLIENT) {
- spin_lock(&zcache_rem_op_list_lock);
- list_add_tail(&zv->rem_op.list, &zcache_rem_op_list);
- spin_unlock(&zcache_rem_op_list_lock);
- }
- memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen);
- kunmap_atomic(zv);
-out:
- return zv;
-}
-
-/* similar to zv_create, but just reserve space, no data yet */
-static struct zv_hdr *zv_alloc(struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index,
- unsigned clen)
-{
- struct zcache_client *cli = pool->client;
- struct page *page;
- struct zv_hdr *zv = NULL;
- uint32_t offset;
- int ret;
-
- BUG_ON(!irqs_disabled());
- BUG_ON(!is_local_client(pool->client));
- ret = xv_malloc(cli->xvpool, clen + sizeof(struct zv_hdr),
- &page, &offset, ZCACHE_GFP_MASK);
- if (unlikely(ret))
- goto out;
- zv = kmap_atomic(page) + offset;
- SET_SENTINEL(zv, ZVH);
- INIT_LIST_HEAD(&zv->rem_op.list);
- zv->client_id = LOCAL_CLIENT;
- zv->rem_op.op = RAMSTER_INTRANSIT_PERS;
- zv->index = index;
- zv->oid = *oid;
- zv->pool_id = pool->pool_id;
- kunmap_atomic(zv);
-out:
- return zv;
-}
-
-static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv)
-{
- unsigned long flags;
- struct page *page;
- uint32_t offset;
- uint16_t size = xv_get_object_size(zv);
- int chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT;
-
- ASSERT_SENTINEL(zv, ZVH);
- BUG_ON(chunks >= NCHUNKS);
- atomic_dec(&zv_curr_dist_counts[chunks]);
- size -= sizeof(*zv);
- spin_lock(&zcache_rem_op_list_lock);
- size = xv_get_object_size(zv) - sizeof(*zv);
- BUG_ON(size == 0);
- INVERT_SENTINEL(zv, ZVH);
- if (!list_empty(&zv->rem_op.list))
- list_del_init(&zv->rem_op.list);
- spin_unlock(&zcache_rem_op_list_lock);
- page = virt_to_page(zv);
- offset = (unsigned long)zv & ~PAGE_MASK;
- local_irq_save(flags);
- xv_free(xvpool, page, offset);
- local_irq_restore(flags);
-}
-
-static void zv_decompress(struct page *page, struct zv_hdr *zv)
-{
- size_t clen = PAGE_SIZE;
- char *to_va;
- unsigned size;
- int ret;
-
- ASSERT_SENTINEL(zv, ZVH);
- size = xv_get_object_size(zv) - sizeof(*zv);
- BUG_ON(size == 0);
- to_va = kmap_atomic(page);
- ret = lzo1x_decompress_safe((char *)zv + sizeof(*zv),
- size, to_va, &clen);
- kunmap_atomic(to_va);
- BUG_ON(ret != LZO_E_OK);
- BUG_ON(clen != PAGE_SIZE);
-}
-
-static void zv_copy_from_pampd(char *data, size_t *bufsize, struct zv_hdr *zv)
-{
- unsigned size;
-
- ASSERT_SENTINEL(zv, ZVH);
- size = xv_get_object_size(zv) - sizeof(*zv);
- BUG_ON(size == 0 || size > zv_max_page_size);
- BUG_ON(size > *bufsize);
- memcpy(data, (char *)zv + sizeof(*zv), size);
- *bufsize = size;
-}
-
-static void zv_copy_to_pampd(struct zv_hdr *zv, char *data, size_t size)
-{
- unsigned zv_size;
-
- ASSERT_SENTINEL(zv, ZVH);
- zv_size = xv_get_object_size(zv) - sizeof(*zv);
- BUG_ON(zv_size != size);
- BUG_ON(zv_size == 0 || zv_size > zv_max_page_size);
- memcpy((char *)zv + sizeof(*zv), data, size);
-}
-
-#ifdef CONFIG_SYSFS
-/*
- * show a distribution of compression stats for zv pages.
- */
-
-static int zv_curr_dist_counts_show(char *buf)
-{
- unsigned long i, n, chunks = 0, sum_total_chunks = 0;
- char *p = buf;
-
- for (i = 0; i < NCHUNKS; i++) {
- n = atomic_read(&zv_curr_dist_counts[i]);
- p += sprintf(p, "%lu ", n);
- chunks += n;
- sum_total_chunks += i * n;
- }
- p += sprintf(p, "mean:%lu\n",
- chunks == 0 ? 0 : sum_total_chunks / chunks);
- return p - buf;
-}
-
-static int zv_cumul_dist_counts_show(char *buf)
-{
- unsigned long i, n, chunks = 0, sum_total_chunks = 0;
- char *p = buf;
-
- for (i = 0; i < NCHUNKS; i++) {
- n = atomic_read(&zv_cumul_dist_counts[i]);
- p += sprintf(p, "%lu ", n);
- chunks += n;
- sum_total_chunks += i * n;
- }
- p += sprintf(p, "mean:%lu\n",
- chunks == 0 ? 0 : sum_total_chunks / chunks);
- return p - buf;
-}
-
-/*
- * setting zv_max_zsize via sysfs causes all persistent (e.g. swap)
- * pages that don't compress to less than this value (including metadata
- * overhead) to be rejected. We don't allow the value to get too close
- * to PAGE_SIZE.
- */
-static ssize_t zv_max_zsize_show(struct kobject *kobj,
- struct kobj_attribute *attr,
- char *buf)
-{
- return sprintf(buf, "%u\n", zv_max_zsize);
-}
-
-static ssize_t zv_max_zsize_store(struct kobject *kobj,
- struct kobj_attribute *attr,
- const char *buf, size_t count)
-{
- unsigned long val;
- int err;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- err = kstrtoul(buf, 10, &val);
- if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7))
- return -EINVAL;
- zv_max_zsize = val;
- return count;
-}
-
-/*
- * setting zv_max_mean_zsize via sysfs causes all persistent (e.g. swap)
- * pages that don't compress to less than this value (including metadata
- * overhead) to be rejected UNLESS the mean compression is also smaller
- * than this value. In other words, we are load-balancing-by-zsize the
- * accepted pages. Again, we don't allow the value to get too close
- * to PAGE_SIZE.
- */
-static ssize_t zv_max_mean_zsize_show(struct kobject *kobj,
- struct kobj_attribute *attr,
- char *buf)
-{
- return sprintf(buf, "%u\n", zv_max_mean_zsize);
-}
-
-static ssize_t zv_max_mean_zsize_store(struct kobject *kobj,
- struct kobj_attribute *attr,
- const char *buf, size_t count)
-{
- unsigned long val;
- int err;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- err = kstrtoul(buf, 10, &val);
- if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7))
- return -EINVAL;
- zv_max_mean_zsize = val;
- return count;
-}
-
-/*
- * setting zv_page_count_policy_percent via sysfs sets an upper bound of
- * persistent (e.g. swap) pages that will be retained according to:
- * (zv_page_count_policy_percent * totalram_pages) / 100)
- * when that limit is reached, further puts will be rejected (until
- * some pages have been flushed). Note that, due to compression,
- * this number may exceed 100; it defaults to 75 and we set an
- * arbitrary limit of 150. A poor choice will almost certainly result
- * in OOM's, so this value should only be changed prudently.
- */
-static ssize_t zv_page_count_policy_percent_show(struct kobject *kobj,
- struct kobj_attribute *attr,
- char *buf)
-{
- return sprintf(buf, "%u\n", zv_page_count_policy_percent);
-}
-
-static ssize_t zv_page_count_policy_percent_store(struct kobject *kobj,
- struct kobj_attribute *attr,
- const char *buf, size_t count)
-{
- unsigned long val;
- int err;
-
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
-
- err = kstrtoul(buf, 10, &val);
- if (err || (val == 0) || (val > 150))
- return -EINVAL;
- zv_page_count_policy_percent = val;
- return count;
-}
-
-static struct kobj_attribute zcache_zv_max_zsize_attr = {
- .attr = { .name = "zv_max_zsize", .mode = 0644 },
- .show = zv_max_zsize_show,
- .store = zv_max_zsize_store,
-};
-
-static struct kobj_attribute zcache_zv_max_mean_zsize_attr = {
- .attr = { .name = "zv_max_mean_zsize", .mode = 0644 },
- .show = zv_max_mean_zsize_show,
- .store = zv_max_mean_zsize_store,
-};
-
-static struct kobj_attribute zcache_zv_page_count_policy_percent_attr = {
- .attr = { .name = "zv_page_count_policy_percent",
- .mode = 0644 },
- .show = zv_page_count_policy_percent_show,
- .store = zv_page_count_policy_percent_store,
-};
-#endif
-
-/*
- * zcache core code starts here
- */
-
-/* useful stats not collected by cleancache or frontswap */
-static unsigned long zcache_flush_total;
-static unsigned long zcache_flush_found;
-static unsigned long zcache_flobj_total;
-static unsigned long zcache_flobj_found;
-static unsigned long zcache_failed_eph_puts;
-static unsigned long zcache_nonactive_puts;
-static unsigned long zcache_failed_pers_puts;
-
-/*
- * Tmem operations assume the poolid implies the invoking client.
- * Zcache only has one client (the kernel itself): LOCAL_CLIENT.
- * RAMster has each client numbered by cluster node, and a KVM version
- * of zcache would have one client per guest and each client might
- * have a poolid==N.
- */
-static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid)
-{
- struct tmem_pool *pool = NULL;
- struct zcache_client *cli = NULL;
-
- if (cli_id == LOCAL_CLIENT)
- cli = &zcache_host;
- else {
- if (cli_id >= MAX_CLIENTS)
- goto out;
- cli = &zcache_clients[cli_id];
- if (cli == NULL)
- goto out;
- atomic_inc(&cli->refcount);
- }
- if (poolid < MAX_POOLS_PER_CLIENT) {
- pool = cli->tmem_pools[poolid];
- if (pool != NULL)
- atomic_inc(&pool->refcount);
- }
-out:
- return pool;
-}
-
-static void zcache_put_pool(struct tmem_pool *pool)
-{
- struct zcache_client *cli = NULL;
-
- if (pool == NULL)
- BUG();
- cli = pool->client;
- atomic_dec(&pool->refcount);
- atomic_dec(&cli->refcount);
-}
-
-int zcache_new_client(uint16_t cli_id)
-{
- struct zcache_client *cli = NULL;
- int ret = -1;
-
- if (cli_id == LOCAL_CLIENT)
- cli = &zcache_host;
- else if ((unsigned int)cli_id < MAX_CLIENTS)
- cli = &zcache_clients[cli_id];
- if (cli == NULL)
- goto out;
- if (cli->allocated)
- goto out;
- cli->allocated = 1;
-#ifdef CONFIG_FRONTSWAP
- cli->xvpool = xv_create_pool();
- if (cli->xvpool == NULL)
- goto out;
-#endif
- ret = 0;
-out:
- return ret;
-}
-
-/* counters for debugging */
-static unsigned long zcache_failed_get_free_pages;
-static unsigned long zcache_failed_alloc;
-static unsigned long zcache_put_to_flush;
-
-/*
- * for now, used named slabs so can easily track usage; later can
- * either just use kmalloc, or perhaps add a slab-like allocator
- * to more carefully manage total memory utilization
- */
-static struct kmem_cache *zcache_objnode_cache;
-static struct kmem_cache *zcache_obj_cache;
-static struct kmem_cache *ramster_flnode_cache;
-static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0);
-static unsigned long zcache_curr_obj_count_max;
-static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0);
-static unsigned long zcache_curr_objnode_count_max;
-
-/*
- * to avoid memory allocation recursion (e.g. due to direct reclaim), we
- * preload all necessary data structures so the hostops callbacks never
- * actually do a malloc
- */
-struct zcache_preload {
- void *page;
- struct tmem_obj *obj;
- int nr;
- struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH];
- struct flushlist_node *flnode;
-};
-static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, };
-
-static int zcache_do_preload(struct tmem_pool *pool)
-{
- struct zcache_preload *kp;
- struct tmem_objnode *objnode;
- struct tmem_obj *obj;
- struct flushlist_node *flnode;
- void *page;
- int ret = -ENOMEM;
-
- if (unlikely(zcache_objnode_cache == NULL))
- goto out;
- if (unlikely(zcache_obj_cache == NULL))
- goto out;
- preempt_disable();
- kp = &__get_cpu_var(zcache_preloads);
- while (kp->nr < ARRAY_SIZE(kp->objnodes)) {
- preempt_enable_no_resched();
- objnode = kmem_cache_alloc(zcache_objnode_cache,
- ZCACHE_GFP_MASK);
- if (unlikely(objnode == NULL)) {
- zcache_failed_alloc++;
- goto out;
- }
- preempt_disable();
- kp = &__get_cpu_var(zcache_preloads);
- if (kp->nr < ARRAY_SIZE(kp->objnodes))
- kp->objnodes[kp->nr++] = objnode;
- else
- kmem_cache_free(zcache_objnode_cache, objnode);
- }
- preempt_enable_no_resched();
- obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK);
- if (unlikely(obj == NULL)) {
- zcache_failed_alloc++;
- goto out;
- }
- flnode = kmem_cache_alloc(ramster_flnode_cache, ZCACHE_GFP_MASK);
- if (unlikely(flnode == NULL)) {
- zcache_failed_alloc++;
- goto out;
- }
- if (is_ephemeral(pool)) {
- page = (void *)__get_free_page(ZCACHE_GFP_MASK);
- if (unlikely(page == NULL)) {
- zcache_failed_get_free_pages++;
- kmem_cache_free(zcache_obj_cache, obj);
- kmem_cache_free(ramster_flnode_cache, flnode);
- goto out;
- }
- }
- preempt_disable();
- kp = &__get_cpu_var(zcache_preloads);
- if (kp->obj == NULL)
- kp->obj = obj;
- else
- kmem_cache_free(zcache_obj_cache, obj);
- if (kp->flnode == NULL)
- kp->flnode = flnode;
- else
- kmem_cache_free(ramster_flnode_cache, flnode);
- if (is_ephemeral(pool)) {
- if (kp->page == NULL)
- kp->page = page;
- else
- free_page((unsigned long)page);
- }
- ret = 0;
-out:
- return ret;
-}
-
-static int ramster_do_preload_flnode_only(struct tmem_pool *pool)
-{
- struct zcache_preload *kp;
- struct flushlist_node *flnode;
- int ret = -ENOMEM;
-
- BUG_ON(!irqs_disabled());
- if (unlikely(ramster_flnode_cache == NULL))
- BUG();
- kp = &__get_cpu_var(zcache_preloads);
- flnode = kmem_cache_alloc(ramster_flnode_cache, GFP_ATOMIC);
- if (unlikely(flnode == NULL) && kp->flnode == NULL)
- BUG(); /* FIXME handle more gracefully, but how??? */
- else if (kp->flnode == NULL)
- kp->flnode = flnode;
- else
- kmem_cache_free(ramster_flnode_cache, flnode);
- return ret;
-}
-
-static void *zcache_get_free_page(void)
-{
- struct zcache_preload *kp;
- void *page;
-
- kp = &__get_cpu_var(zcache_preloads);
- page = kp->page;
- BUG_ON(page == NULL);
- kp->page = NULL;
- return page;
-}
-
-static void zcache_free_page(void *p)
-{
- free_page((unsigned long)p);
-}
-
-/*
- * zcache implementation for tmem host ops
- */
-
-static struct tmem_objnode *zcache_objnode_alloc(struct tmem_pool *pool)
-{
- struct tmem_objnode *objnode = NULL;
- unsigned long count;
- struct zcache_preload *kp;
-
- kp = &__get_cpu_var(zcache_preloads);
- if (kp->nr <= 0)
- goto out;
- objnode = kp->objnodes[kp->nr - 1];
- BUG_ON(objnode == NULL);
- kp->objnodes[kp->nr - 1] = NULL;
- kp->nr--;
- count = atomic_inc_return(&zcache_curr_objnode_count);
- if (count > zcache_curr_objnode_count_max)
- zcache_curr_objnode_count_max = count;
-out:
- return objnode;
-}
-
-static void zcache_objnode_free(struct tmem_objnode *objnode,
- struct tmem_pool *pool)
-{
- atomic_dec(&zcache_curr_objnode_count);
- BUG_ON(atomic_read(&zcache_curr_objnode_count) < 0);
- kmem_cache_free(zcache_objnode_cache, objnode);
-}
-
-static struct tmem_obj *zcache_obj_alloc(struct tmem_pool *pool)
-{
- struct tmem_obj *obj = NULL;
- unsigned long count;
- struct zcache_preload *kp;
-
- kp = &__get_cpu_var(zcache_preloads);
- obj = kp->obj;
- BUG_ON(obj == NULL);
- kp->obj = NULL;
- count = atomic_inc_return(&zcache_curr_obj_count);
- if (count > zcache_curr_obj_count_max)
- zcache_curr_obj_count_max = count;
- return obj;
-}
-
-static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool)
-{
- atomic_dec(&zcache_curr_obj_count);
- BUG_ON(atomic_read(&zcache_curr_obj_count) < 0);
- kmem_cache_free(zcache_obj_cache, obj);
-}
-
-static struct flushlist_node *ramster_flnode_alloc(struct tmem_pool *pool)
-{
- struct flushlist_node *flnode = NULL;
- struct zcache_preload *kp;
- int count;
-
- kp = &__get_cpu_var(zcache_preloads);
- flnode = kp->flnode;
- BUG_ON(flnode == NULL);
- kp->flnode = NULL;
- count = atomic_inc_return(&ramster_curr_flnode_count);
- if (count > ramster_curr_flnode_count_max)
- ramster_curr_flnode_count_max = count;
- return flnode;
-}
-
-static void ramster_flnode_free(struct flushlist_node *flnode,
- struct tmem_pool *pool)
-{
- atomic_dec(&ramster_curr_flnode_count);
- BUG_ON(atomic_read(&ramster_curr_flnode_count) < 0);
- kmem_cache_free(ramster_flnode_cache, flnode);
-}
-
-static struct tmem_hostops zcache_hostops = {
- .obj_alloc = zcache_obj_alloc,
- .obj_free = zcache_obj_free,
- .objnode_alloc = zcache_objnode_alloc,
- .objnode_free = zcache_objnode_free,
-};
-
-/*
- * zcache implementations for PAM page descriptor ops
- */
-
-
-static inline void dec_and_check(atomic_t *pvar)
-{
- atomic_dec(pvar);
- /* later when all accounting is fixed, make this a BUG */
- WARN_ON_ONCE(atomic_read(pvar) < 0);
-}
-
-static atomic_t zcache_curr_eph_pampd_count = ATOMIC_INIT(0);
-static unsigned long zcache_curr_eph_pampd_count_max;
-static atomic_t zcache_curr_pers_pampd_count = ATOMIC_INIT(0);
-static unsigned long zcache_curr_pers_pampd_count_max;
-
-/* forward reference */
-static int zcache_compress(struct page *from, void **out_va, size_t *out_len);
-
-static int zcache_pampd_eph_create(char *data, size_t size, bool raw,
- struct tmem_pool *pool, struct tmem_oid *oid,
- uint32_t index, void **pampd)
-{
- int ret = -1;
- void *cdata = data;
- size_t clen = size;
- struct zcache_client *cli = pool->client;
- uint16_t client_id = get_client_id_from_client(cli);
- struct page *page = NULL;
- unsigned long count;
-
- if (!raw) {
- page = virt_to_page(data);
- ret = zcache_compress(page, &cdata, &clen);
- if (ret == 0)
- goto out;
- if (clen == 0 || clen > zbud_max_buddy_size()) {
- zcache_compress_poor++;
- goto out;
- }
- }
- *pampd = (void *)zbud_create(client_id, pool->pool_id, oid,
- index, page, cdata, clen);
- if (*pampd == NULL) {
- ret = -ENOMEM;
- goto out;
- }
- ret = 0;
- count = atomic_inc_return(&zcache_curr_eph_pampd_count);
- if (count > zcache_curr_eph_pampd_count_max)
- zcache_curr_eph_pampd_count_max = count;
- if (client_id != LOCAL_CLIENT) {
- count = atomic_inc_return(&ramster_foreign_eph_pampd_count);
- if (count > ramster_foreign_eph_pampd_count_max)
- ramster_foreign_eph_pampd_count_max = count;
- }
-out:
- return ret;
-}
-
-static int zcache_pampd_pers_create(char *data, size_t size, bool raw,
- struct tmem_pool *pool, struct tmem_oid *oid,
- uint32_t index, void **pampd)
-{
- int ret = -1;
- void *cdata = data;
- size_t clen = size;
- struct zcache_client *cli = pool->client;
- struct page *page;
- unsigned long count;
- unsigned long zv_mean_zsize;
- struct zv_hdr *zv;
- long curr_pers_pampd_count;
- u64 total_zsize;
-#ifdef RAMSTER_TESTING
- static bool pampd_neg_warned;
-#endif
-
- curr_pers_pampd_count = atomic_read(&zcache_curr_pers_pampd_count) -
- atomic_read(&ramster_remote_pers_pages);
-#ifdef RAMSTER_TESTING
- /* should always be positive, but warn if accounting is off */
- if (!pampd_neg_warned) {
- pr_warn("ramster: bad accounting for curr_pers_pampd_count\n");
- pampd_neg_warned = true;
- }
-#endif
- if (curr_pers_pampd_count >
- (zv_page_count_policy_percent * totalram_pages) / 100) {
- zcache_policy_percent_exceeded++;
- goto out;
- }
- if (raw)
- goto ok_to_create;
- page = virt_to_page(data);
- if (zcache_compress(page, &cdata, &clen) == 0)
- goto out;
- /* reject if compression is too poor */
- if (clen > zv_max_zsize) {
- zcache_compress_poor++;
- goto out;
- }
- /* reject if mean compression is too poor */
- if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) {
- total_zsize = xv_get_total_size_bytes(cli->xvpool);
- zv_mean_zsize = div_u64(total_zsize, curr_pers_pampd_count);
- if (zv_mean_zsize > zv_max_mean_zsize) {
- zcache_mean_compress_poor++;
- goto out;
- }
- }
-ok_to_create:
- *pampd = (void *)zv_create(cli, pool->pool_id, oid, index, cdata, clen);
- if (*pampd == NULL) {
- ret = -ENOMEM;
- goto out;
- }
- ret = 0;
- count = atomic_inc_return(&zcache_curr_pers_pampd_count);
- if (count > zcache_curr_pers_pampd_count_max)
- zcache_curr_pers_pampd_count_max = count;
- if (is_local_client(cli))
- goto out;
- zv = *(struct zv_hdr **)pampd;
- count = atomic_inc_return(&ramster_foreign_pers_pampd_count);
- if (count > ramster_foreign_pers_pampd_count_max)
- ramster_foreign_pers_pampd_count_max = count;
-out:
- return ret;
-}
-
-static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph,
- struct tmem_pool *pool, struct tmem_oid *oid,
- uint32_t index)
-{
- void *pampd = NULL;
- int ret;
- bool ephemeral;
-
- BUG_ON(preemptible());
- ephemeral = (eph == 1) || ((eph == 0) && is_ephemeral(pool));
- if (ephemeral)
- ret = zcache_pampd_eph_create(data, size, raw, pool,
- oid, index, &pampd);
- else
- ret = zcache_pampd_pers_create(data, size, raw, pool,
- oid, index, &pampd);
- /* FIXME add some counters here for failed creates? */
- return pampd;
-}
-
-/*
- * fill the pageframe corresponding to the struct page with the data
- * from the passed pampd
- */
-static int zcache_pampd_get_data(char *data, size_t *bufsize, bool raw,
- void *pampd, struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index)
-{
- int ret = 0;
-
- BUG_ON(preemptible());
- BUG_ON(is_ephemeral(pool)); /* Fix later for shared pools? */
- BUG_ON(pampd_is_remote(pampd));
- if (raw)
- zv_copy_from_pampd(data, bufsize, pampd);
- else
- zv_decompress(virt_to_page(data), pampd);
- return ret;
-}
-
-static int zcache_pampd_get_data_and_free(char *data, size_t *bufsize, bool raw,
- void *pampd, struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index)
-{
- int ret = 0;
- unsigned long flags;
- struct zcache_client *cli = pool->client;
-
- BUG_ON(preemptible());
- BUG_ON(pampd_is_remote(pampd));
- if (is_ephemeral(pool)) {
- local_irq_save(flags);
- if (raw)
- zbud_copy_from_pampd(data, bufsize, pampd);
- else
- ret = zbud_decompress(virt_to_page(data), pampd);
- zbud_free_and_delist((struct zbud_hdr *)pampd);
- local_irq_restore(flags);
- if (!is_local_client(cli))
- dec_and_check(&ramster_foreign_eph_pampd_count);
- dec_and_check(&zcache_curr_eph_pampd_count);
- } else {
- if (is_local_client(cli))
- BUG();
- if (raw)
- zv_copy_from_pampd(data, bufsize, pampd);
- else
- zv_decompress(virt_to_page(data), pampd);
- zv_free(cli->xvpool, pampd);
- if (!is_local_client(cli))
- dec_and_check(&ramster_foreign_pers_pampd_count);
- dec_and_check(&zcache_curr_pers_pampd_count);
- ret = 0;
- }
- return ret;
-}
-
-static bool zcache_pampd_is_remote(void *pampd)
-{
- return pampd_is_remote(pampd);
-}
-
-/*
- * free the pampd and remove it from any zcache lists
- * pampd must no longer be pointed to from any tmem data structures!
- */
-static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index, bool acct)
-{
- struct zcache_client *cli = pool->client;
- bool eph = is_ephemeral(pool);
- struct zv_hdr *zv;
-
- BUG_ON(preemptible());
- if (pampd_is_remote(pampd)) {
- WARN_ON(acct == false);
- if (oid == NULL) {
- /*
- * a NULL oid means to ignore this pampd free
- * as the remote freeing will be handled elsewhere
- */
- } else if (eph) {
- /* FIXME remote flush optional but probably good idea */
- /* FIXME get these working properly again */
- dec_and_check(&zcache_curr_eph_pampd_count);
- } else if (pampd_is_intransit(pampd)) {
- /* did a pers remote get_and_free, so just free local */
- pampd = pampd_mask_intransit_and_remote(pampd);
- goto local_pers;
- } else {
- struct flushlist_node *flnode =
- ramster_flnode_alloc(pool);
-
- flnode->xh.client_id = pampd_remote_node(pampd);
- flnode->xh.pool_id = pool->pool_id;
- flnode->xh.oid = *oid;
- flnode->xh.index = index;
- flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_PAGE;
- spin_lock(&zcache_rem_op_list_lock);
- list_add(&flnode->rem_op.list, &zcache_rem_op_list);
- spin_unlock(&zcache_rem_op_list_lock);
- dec_and_check(&zcache_curr_pers_pampd_count);
- dec_and_check(&ramster_remote_pers_pages);
- }
- } else if (eph) {
- zbud_free_and_delist((struct zbud_hdr *)pampd);
- if (!is_local_client(pool->client))
- dec_and_check(&ramster_foreign_eph_pampd_count);
- if (acct)
- /* FIXME get these working properly again */
- dec_and_check(&zcache_curr_eph_pampd_count);
- } else {
-local_pers:
- zv = (struct zv_hdr *)pampd;
- if (!is_local_client(pool->client))
- dec_and_check(&ramster_foreign_pers_pampd_count);
- zv_free(cli->xvpool, zv);
- if (acct)
- /* FIXME get these working properly again */
- dec_and_check(&zcache_curr_pers_pampd_count);
- }
-}
-
-static void zcache_pampd_free_obj(struct tmem_pool *pool,
- struct tmem_obj *obj)
-{
- struct flushlist_node *flnode;
-
- BUG_ON(preemptible());
- if (obj->extra == NULL)
- return;
- BUG_ON(!pampd_is_remote(obj->extra));
- flnode = ramster_flnode_alloc(pool);
- flnode->xh.client_id = pampd_remote_node(obj->extra);
- flnode->xh.pool_id = pool->pool_id;
- flnode->xh.oid = obj->oid;
- flnode->xh.index = FLUSH_ENTIRE_OBJECT;
- flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_OBJ;
- spin_lock(&zcache_rem_op_list_lock);
- list_add(&flnode->rem_op.list, &zcache_rem_op_list);
- spin_unlock(&zcache_rem_op_list_lock);
-}
-
-void zcache_pampd_new_obj(struct tmem_obj *obj)
-{
- obj->extra = NULL;
-}
-
-int zcache_pampd_replace_in_obj(void *new_pampd, struct tmem_obj *obj)
-{
- int ret = -1;
-
- if (new_pampd != NULL) {
- if (obj->extra == NULL)
- obj->extra = new_pampd;
- /* enforce that all remote pages in an object reside
- * in the same node! */
- else if (pampd_remote_node(new_pampd) !=
- pampd_remote_node((void *)(obj->extra)))
- BUG();
- ret = 0;
- }
- return ret;
-}
-
-/*
- * Called by the message handler after a (still compressed) page has been
- * fetched from the remote machine in response to an "is_remote" tmem_get
- * or persistent tmem_localify. For a tmem_get, "extra" is the address of
- * the page that is to be filled to successfully resolve the tmem_get; for
- * a (persistent) tmem_localify, "extra" is NULL (as the data is placed only
- * in the local zcache). "data" points to "size" bytes of (compressed) data
- * passed in the message. In the case of a persistent remote get, if
- * pre-allocation was successful (see zcache_repatriate_preload), the page
- * is placed into both local zcache and at "extra".
- */
-int zcache_localify(int pool_id, struct tmem_oid *oidp,
- uint32_t index, char *data, size_t size,
- void *extra)
-{
- int ret = -ENOENT;
- unsigned long flags;
- struct tmem_pool *pool;
- bool ephemeral, delete = false;
- size_t clen = PAGE_SIZE;
- void *pampd, *saved_hb;
- struct tmem_obj *obj;
-
- pool = zcache_get_pool_by_id(LOCAL_CLIENT, pool_id);
- if (unlikely(pool == NULL))
- /* pool doesn't exist anymore */
- goto out;
- ephemeral = is_ephemeral(pool);
- local_irq_save(flags); /* FIXME: maybe only disable softirqs? */
- pampd = tmem_localify_get_pampd(pool, oidp, index, &obj, &saved_hb);
- if (pampd == NULL) {
- /* hmmm... must have been a flush while waiting */
-#ifdef RAMSTER_TESTING
- pr_err("UNTESTED pampd==NULL in zcache_localify\n");
-#endif
- if (ephemeral)
- ramster_remote_eph_pages_unsucc_get++;
- else
- ramster_remote_pers_pages_unsucc_get++;
- obj = NULL;
- goto finish;
- } else if (unlikely(!pampd_is_remote(pampd))) {
- /* hmmm... must have been a dup put while waiting */
-#ifdef RAMSTER_TESTING
- pr_err("UNTESTED dup while waiting in zcache_localify\n");
-#endif
- if (ephemeral)
- ramster_remote_eph_pages_unsucc_get++;
- else
- ramster_remote_pers_pages_unsucc_get++;
- obj = NULL;
- pampd = NULL;
- ret = -EEXIST;
- goto finish;
- } else if (size == 0) {
- /* no remote data, delete the local is_remote pampd */
- pampd = NULL;
- if (ephemeral)
- ramster_remote_eph_pages_unsucc_get++;
- else
- BUG();
- delete = true;
- goto finish;
- }
- if (!ephemeral && pampd_is_intransit(pampd)) {
- /* localify to zcache */
- pampd = pampd_mask_intransit_and_remote(pampd);
- zv_copy_to_pampd(pampd, data, size);
- } else {
- pampd = NULL;
- obj = NULL;
- }
- if (extra != NULL) {
- /* decompress direct-to-memory to complete remotify */
- ret = lzo1x_decompress_safe((char *)data, size,
- (char *)extra, &clen);
- BUG_ON(ret != LZO_E_OK);
- BUG_ON(clen != PAGE_SIZE);
- }
- if (ephemeral)
- ramster_remote_eph_pages_succ_get++;
- else
- ramster_remote_pers_pages_succ_get++;
- ret = 0;
-finish:
- tmem_localify_finish(obj, index, pampd, saved_hb, delete);
- zcache_put_pool(pool);
- local_irq_restore(flags);
-out:
- return ret;
-}
-
-/*
- * Called on a remote persistent tmem_get to attempt to preallocate
- * local storage for the data contained in the remote persistent page.
- * If successfully preallocated, returns the pampd, marked as remote and
- * in_transit. Else returns NULL. Note that the appropriate tmem data
- * structure must be locked.
- */
-static void *zcache_pampd_repatriate_preload(void *pampd,
- struct tmem_pool *pool,
- struct tmem_oid *oid,
- uint32_t index,
- bool *intransit)
-{
- int clen = pampd_remote_size(pampd);
- void *ret_pampd = NULL;
- unsigned long flags;
-
- if (!pampd_is_remote(pampd))
- BUG();
- if (is_ephemeral(pool))
- BUG();
- if (pampd_is_intransit(pampd)) {
- /*
- * to avoid multiple allocations (and maybe a memory leak)
- * don't preallocate if already in the process of being
- * repatriated
- */
- *intransit = true;
- goto out;
- }
- *intransit = false;
- local_irq_save(flags);
- ret_pampd = (void *)zv_alloc(pool, oid, index, clen);
- if (ret_pampd != NULL) {
- /*
- * a pampd is marked intransit if it is remote and space has
- * been allocated for it locally (note, only happens for
- * persistent pages, in which case the remote copy is freed)
- */
- ret_pampd = pampd_mark_intransit(ret_pampd);
- dec_and_check(&ramster_remote_pers_pages);
- } else
- ramster_pers_pages_remote_nomem++;
- local_irq_restore(flags);
-out:
- return ret_pampd;
-}
-
-/*
- * Called on a remote tmem_get to invoke a message to fetch the page.
- * Might sleep so no tmem locks can be held. "extra" is passed
- * all the way through the round-trip messaging to zcache_localify.
- */
-static int zcache_pampd_repatriate(void *fake_pampd, void *real_pampd,
- struct tmem_pool *pool,
- struct tmem_oid *oid, uint32_t index,
- bool free, void *extra)
-{
- struct tmem_xhandle xh;
- int ret;
-
- if (pampd_is_intransit(real_pampd))
- /* have local space pre-reserved, so free remote copy */
- free = true;
- xh = tmem_xhandle_fill(LOCAL_CLIENT, pool, oid, index);
- /* unreliable request/response for now */
- ret = ramster_remote_async_get(&xh, free,
- pampd_remote_node(fake_pampd),
- pampd_remote_size(fake_pampd),
- pampd_remote_cksum(fake_pampd),
- extra);
-#ifdef RAMSTER_TESTING
- if (ret != 0 && ret != -ENOENT)
- pr_err("TESTING zcache_pampd_repatriate returns, ret=%d\n",
- ret);
-#endif
- return ret;
-}
-
-static struct tmem_pamops zcache_pamops = {
- .create = zcache_pampd_create,
- .get_data = zcache_pampd_get_data,
- .free = zcache_pampd_free,
- .get_data_and_free = zcache_pampd_get_data_and_free,
- .free_obj = zcache_pampd_free_obj,
- .is_remote = zcache_pampd_is_remote,
- .repatriate_preload = zcache_pampd_repatriate_preload,
- .repatriate = zcache_pampd_repatriate,
- .new_obj = zcache_pampd_new_obj,
- .replace_in_obj = zcache_pampd_replace_in_obj,
-};
-
-/*
- * zcache compression/decompression and related per-cpu stuff
- */
-
-#define LZO_WORKMEM_BYTES LZO1X_1_MEM_COMPRESS
-#define LZO_DSTMEM_PAGE_ORDER 1
-static DEFINE_PER_CPU(unsigned char *, zcache_workmem);
-static DEFINE_PER_CPU(unsigned char *, zcache_dstmem);
-
-static int zcache_compress(struct page *from, void **out_va, size_t *out_len)
-{
- int ret = 0;
- unsigned char *dmem = __get_cpu_var(zcache_dstmem);
- unsigned char *wmem = __get_cpu_var(zcache_workmem);
- char *from_va;
-
- BUG_ON(!irqs_disabled());
- if (unlikely(dmem == NULL || wmem == NULL))
- goto out; /* no buffer, so can't compress */
- from_va = kmap_atomic(from);
- mb();
- ret = lzo1x_1_compress(from_va, PAGE_SIZE, dmem, out_len, wmem);
- BUG_ON(ret != LZO_E_OK);
- *out_va = dmem;
- kunmap_atomic(from_va);
- ret = 1;
-out:
- return ret;
-}
-
-
-static int zcache_cpu_notifier(struct notifier_block *nb,
- unsigned long action, void *pcpu)
-{
- int cpu = (long)pcpu;
- struct zcache_preload *kp;
-
- switch (action) {
- case CPU_UP_PREPARE:
- per_cpu(zcache_dstmem, cpu) = (void *)__get_free_pages(
- GFP_KERNEL | __GFP_REPEAT,
- LZO_DSTMEM_PAGE_ORDER),
- per_cpu(zcache_workmem, cpu) =
- kzalloc(LZO1X_MEM_COMPRESS,
- GFP_KERNEL | __GFP_REPEAT);
- per_cpu(zcache_remoteputmem, cpu) =
- kzalloc(PAGE_SIZE, GFP_KERNEL | __GFP_REPEAT);
- break;
- case CPU_DEAD:
- case CPU_UP_CANCELED:
- kfree(per_cpu(zcache_remoteputmem, cpu));
- per_cpu(zcache_remoteputmem, cpu) = NULL;
- free_pages((unsigned long)per_cpu(zcache_dstmem, cpu),
- LZO_DSTMEM_PAGE_ORDER);
- per_cpu(zcache_dstmem, cpu) = NULL;
- kfree(per_cpu(zcache_workmem, cpu));
- per_cpu(zcache_workmem, cpu) = NULL;
- kp = &per_cpu(zcache_preloads, cpu);
- while (kp->nr) {
- kmem_cache_free(zcache_objnode_cache,
- kp->objnodes[kp->nr - 1]);
- kp->objnodes[kp->nr - 1] = NULL;
- kp->nr--;
- }
- if (kp->obj) {
- kmem_cache_free(zcache_obj_cache, kp->obj);
- kp->obj = NULL;
- }
- if (kp->flnode) {
- kmem_cache_free(ramster_flnode_cache, kp->flnode);
- kp->flnode = NULL;
- }
- if (kp->page) {
- free_page((unsigned long)kp->page);
- kp->page = NULL;
- }
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block zcache_cpu_notifier_block = {
- .notifier_call = zcache_cpu_notifier
-};
-
-#ifdef CONFIG_SYSFS
-#define ZCACHE_SYSFS_RO(_name) \
- static ssize_t zcache_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return sprintf(buf, "%lu\n", zcache_##_name); \
- } \
- static struct kobj_attribute zcache_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = zcache_##_name##_show, \
- }
-
-#define ZCACHE_SYSFS_RO_ATOMIC(_name) \
- static ssize_t zcache_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return sprintf(buf, "%d\n", atomic_read(&zcache_##_name)); \
- } \
- static struct kobj_attribute zcache_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = zcache_##_name##_show, \
- }
-
-#define ZCACHE_SYSFS_RO_CUSTOM(_name, _func) \
- static ssize_t zcache_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return _func(buf); \
- } \
- static struct kobj_attribute zcache_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = zcache_##_name##_show, \
- }
-
-ZCACHE_SYSFS_RO(curr_obj_count_max);
-ZCACHE_SYSFS_RO(curr_objnode_count_max);
-ZCACHE_SYSFS_RO(flush_total);
-ZCACHE_SYSFS_RO(flush_found);
-ZCACHE_SYSFS_RO(flobj_total);
-ZCACHE_SYSFS_RO(flobj_found);
-ZCACHE_SYSFS_RO(failed_eph_puts);
-ZCACHE_SYSFS_RO(nonactive_puts);
-ZCACHE_SYSFS_RO(failed_pers_puts);
-ZCACHE_SYSFS_RO(zbud_curr_zbytes);
-ZCACHE_SYSFS_RO(zbud_cumul_zpages);
-ZCACHE_SYSFS_RO(zbud_cumul_zbytes);
-ZCACHE_SYSFS_RO(zbud_buddied_count);
-ZCACHE_SYSFS_RO(evicted_raw_pages);
-ZCACHE_SYSFS_RO(evicted_unbuddied_pages);
-ZCACHE_SYSFS_RO(evicted_buddied_pages);
-ZCACHE_SYSFS_RO(failed_get_free_pages);
-ZCACHE_SYSFS_RO(failed_alloc);
-ZCACHE_SYSFS_RO(put_to_flush);
-ZCACHE_SYSFS_RO(compress_poor);
-ZCACHE_SYSFS_RO(mean_compress_poor);
-ZCACHE_SYSFS_RO(policy_percent_exceeded);
-ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages);
-ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages);
-ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count);
-ZCACHE_SYSFS_RO_ATOMIC(curr_objnode_count);
-ZCACHE_SYSFS_RO_CUSTOM(zbud_unbuddied_list_counts,
- zbud_show_unbuddied_list_counts);
-ZCACHE_SYSFS_RO_CUSTOM(zbud_cumul_chunk_counts,
- zbud_show_cumul_chunk_counts);
-ZCACHE_SYSFS_RO_CUSTOM(zv_curr_dist_counts,
- zv_curr_dist_counts_show);
-ZCACHE_SYSFS_RO_CUSTOM(zv_cumul_dist_counts,
- zv_cumul_dist_counts_show);
-
-static struct attribute *zcache_attrs[] = {
- &zcache_curr_obj_count_attr.attr,
- &zcache_curr_obj_count_max_attr.attr,
- &zcache_curr_objnode_count_attr.attr,
- &zcache_curr_objnode_count_max_attr.attr,
- &zcache_flush_total_attr.attr,
- &zcache_flobj_total_attr.attr,
- &zcache_flush_found_attr.attr,
- &zcache_flobj_found_attr.attr,
- &zcache_failed_eph_puts_attr.attr,
- &zcache_nonactive_puts_attr.attr,
- &zcache_failed_pers_puts_attr.attr,
- &zcache_policy_percent_exceeded_attr.attr,
- &zcache_compress_poor_attr.attr,
- &zcache_mean_compress_poor_attr.attr,
- &zcache_zbud_curr_raw_pages_attr.attr,
- &zcache_zbud_curr_zpages_attr.attr,
- &zcache_zbud_curr_zbytes_attr.attr,
- &zcache_zbud_cumul_zpages_attr.attr,
- &zcache_zbud_cumul_zbytes_attr.attr,
- &zcache_zbud_buddied_count_attr.attr,
- &zcache_evicted_raw_pages_attr.attr,
- &zcache_evicted_unbuddied_pages_attr.attr,
- &zcache_evicted_buddied_pages_attr.attr,
- &zcache_failed_get_free_pages_attr.attr,
- &zcache_failed_alloc_attr.attr,
- &zcache_put_to_flush_attr.attr,
- &zcache_zbud_unbuddied_list_counts_attr.attr,
- &zcache_zbud_cumul_chunk_counts_attr.attr,
- &zcache_zv_curr_dist_counts_attr.attr,
- &zcache_zv_cumul_dist_counts_attr.attr,
- &zcache_zv_max_zsize_attr.attr,
- &zcache_zv_max_mean_zsize_attr.attr,
- &zcache_zv_page_count_policy_percent_attr.attr,
- NULL,
-};
-
-static struct attribute_group zcache_attr_group = {
- .attrs = zcache_attrs,
- .name = "zcache",
-};
-
-#define RAMSTER_SYSFS_RO(_name) \
- static ssize_t ramster_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return sprintf(buf, "%lu\n", ramster_##_name); \
- } \
- static struct kobj_attribute ramster_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = ramster_##_name##_show, \
- }
-
-#define RAMSTER_SYSFS_RW(_name) \
- static ssize_t ramster_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return sprintf(buf, "%lu\n", ramster_##_name); \
- } \
- static ssize_t ramster_##_name##_store(struct kobject *kobj, \
- struct kobj_attribute *attr, const char *buf, size_t count) \
- { \
- int err; \
- unsigned long enable; \
- err = kstrtoul(buf, 10, &enable); \
- if (err) \
- return -EINVAL; \
- ramster_##_name = enable; \
- return count; \
- } \
- static struct kobj_attribute ramster_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0644 }, \
- .show = ramster_##_name##_show, \
- .store = ramster_##_name##_store, \
- }
-
-#define RAMSTER_SYSFS_RO_ATOMIC(_name) \
- static ssize_t ramster_##_name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, char *buf) \
- { \
- return sprintf(buf, "%d\n", atomic_read(&ramster_##_name)); \
- } \
- static struct kobj_attribute ramster_##_name##_attr = { \
- .attr = { .name = __stringify(_name), .mode = 0444 }, \
- .show = ramster_##_name##_show, \
- }
-
-RAMSTER_SYSFS_RO(interface_revision);
-RAMSTER_SYSFS_RO_ATOMIC(remote_pers_pages);
-RAMSTER_SYSFS_RW(pers_remotify_enable);
-RAMSTER_SYSFS_RW(eph_remotify_enable);
-RAMSTER_SYSFS_RO(eph_pages_remoted);
-RAMSTER_SYSFS_RO(eph_pages_remote_failed);
-RAMSTER_SYSFS_RO(pers_pages_remoted);
-RAMSTER_SYSFS_RO(pers_pages_remote_failed);
-RAMSTER_SYSFS_RO(pers_pages_remote_nomem);
-RAMSTER_SYSFS_RO(remote_pages_flushed);
-RAMSTER_SYSFS_RO(remote_page_flushes_failed);
-RAMSTER_SYSFS_RO(remote_objects_flushed);
-RAMSTER_SYSFS_RO(remote_object_flushes_failed);
-RAMSTER_SYSFS_RO(remote_eph_pages_succ_get);
-RAMSTER_SYSFS_RO(remote_eph_pages_unsucc_get);
-RAMSTER_SYSFS_RO(remote_pers_pages_succ_get);
-RAMSTER_SYSFS_RO(remote_pers_pages_unsucc_get);
-RAMSTER_SYSFS_RO_ATOMIC(foreign_eph_pampd_count);
-RAMSTER_SYSFS_RO(foreign_eph_pampd_count_max);
-RAMSTER_SYSFS_RO_ATOMIC(foreign_pers_pampd_count);
-RAMSTER_SYSFS_RO(foreign_pers_pampd_count_max);
-RAMSTER_SYSFS_RO_ATOMIC(curr_flnode_count);
-RAMSTER_SYSFS_RO(curr_flnode_count_max);
-
-#define MANUAL_NODES 8
-static bool ramster_nodes_manual_up[MANUAL_NODES];
-static ssize_t ramster_manual_node_up_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
-{
- int i;
- char *p = buf;
- for (i = 0; i < MANUAL_NODES; i++)
- if (ramster_nodes_manual_up[i])
- p += sprintf(p, "%d ", i);
- p += sprintf(p, "\n");
- return p - buf;
-}
-
-static ssize_t ramster_manual_node_up_store(struct kobject *kobj,
- struct kobj_attribute *attr, const char *buf, size_t count)
-{
- int err;
- unsigned long node_num;
-
- err = kstrtoul(buf, 10, &node_num);
- if (err) {
- pr_err("ramster: bad strtoul?\n");
- return -EINVAL;
- }
- if (node_num >= MANUAL_NODES) {
- pr_err("ramster: bad node_num=%lu?\n", node_num);
- return -EINVAL;
- }
- if (ramster_nodes_manual_up[node_num]) {
- pr_err("ramster: node %d already up, ignoring\n",
- (int)node_num);
- } else {
- ramster_nodes_manual_up[node_num] = true;
- r2net_hb_node_up_manual((int)node_num);
- }
- return count;
-}
-
-static struct kobj_attribute ramster_manual_node_up_attr = {
- .attr = { .name = "manual_node_up", .mode = 0644 },
- .show = ramster_manual_node_up_show,
- .store = ramster_manual_node_up_store,
-};
-
-static ssize_t ramster_remote_target_nodenum_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
-{
- if (ramster_remote_target_nodenum == -1UL)
- return sprintf(buf, "unset\n");
- else
- return sprintf(buf, "%d\n", ramster_remote_target_nodenum);
-}
-
-static ssize_t ramster_remote_target_nodenum_store(struct kobject *kobj,
- struct kobj_attribute *attr, const char *buf, size_t count)
-{
- int err;
- unsigned long node_num;
-
- err = kstrtoul(buf, 10, &node_num);
- if (err) {
- pr_err("ramster: bad strtoul?\n");
- return -EINVAL;
- } else if (node_num == -1UL) {
- pr_err("ramster: disabling all remotification, "
- "data may still reside on remote nodes however\n");
- return -EINVAL;
- } else if (node_num >= MANUAL_NODES) {
- pr_err("ramster: bad node_num=%lu?\n", node_num);
- return -EINVAL;
- } else if (!ramster_nodes_manual_up[node_num]) {
- pr_err("ramster: node %d not up, ignoring setting "
- "of remotification target\n", (int)node_num);
- } else if (r2net_remote_target_node_set((int)node_num) >= 0) {
- pr_info("ramster: node %d set as remotification target\n",
- (int)node_num);
- ramster_remote_target_nodenum = (int)node_num;
- } else {
- pr_err("ramster: bad num to node node_num=%d?\n",
- (int)node_num);
- return -EINVAL;
- }
- return count;
-}
-
-static struct kobj_attribute ramster_remote_target_nodenum_attr = {
- .attr = { .name = "remote_target_nodenum", .mode = 0644 },
- .show = ramster_remote_target_nodenum_show,
- .store = ramster_remote_target_nodenum_store,
-};
-
-
-static struct attribute *ramster_attrs[] = {
- &ramster_interface_revision_attr.attr,
- &ramster_pers_remotify_enable_attr.attr,
- &ramster_eph_remotify_enable_attr.attr,
- &ramster_remote_pers_pages_attr.attr,
- &ramster_eph_pages_remoted_attr.attr,
- &ramster_eph_pages_remote_failed_attr.attr,
- &ramster_pers_pages_remoted_attr.attr,
- &ramster_pers_pages_remote_failed_attr.attr,
- &ramster_pers_pages_remote_nomem_attr.attr,
- &ramster_remote_pages_flushed_attr.attr,
- &ramster_remote_page_flushes_failed_attr.attr,
- &ramster_remote_objects_flushed_attr.attr,
- &ramster_remote_object_flushes_failed_attr.attr,
- &ramster_remote_eph_pages_succ_get_attr.attr,
- &ramster_remote_eph_pages_unsucc_get_attr.attr,
- &ramster_remote_pers_pages_succ_get_attr.attr,
- &ramster_remote_pers_pages_unsucc_get_attr.attr,
- &ramster_foreign_eph_pampd_count_attr.attr,
- &ramster_foreign_eph_pampd_count_max_attr.attr,
- &ramster_foreign_pers_pampd_count_attr.attr,
- &ramster_foreign_pers_pampd_count_max_attr.attr,
- &ramster_curr_flnode_count_attr.attr,
- &ramster_curr_flnode_count_max_attr.attr,
- &ramster_manual_node_up_attr.attr,
- &ramster_remote_target_nodenum_attr.attr,
- NULL,
-};
-
-static struct attribute_group ramster_attr_group = {
- .attrs = ramster_attrs,
- .name = "ramster",
-};
-
-#endif /* CONFIG_SYSFS */
-/*
- * When zcache is disabled ("frozen"), pools can be created and destroyed,
- * but all puts (and thus all other operations that require memory allocation)
- * must fail. If zcache is unfrozen, accepts puts, then frozen again,
- * data consistency requires all puts while frozen to be converted into
- * flushes.
- */
-static bool zcache_freeze;
-
-/*
- * zcache shrinker interface (only useful for ephemeral pages, so zbud only)
- */
-static int shrink_zcache_memory(struct shrinker *shrink,
- struct shrink_control *sc)
-{
- int ret = -1;
- int nr = sc->nr_to_scan;
- gfp_t gfp_mask = sc->gfp_mask;
-
- if (nr >= 0) {
- if (!(gfp_mask & __GFP_FS))
- /* does this case really need to be skipped? */
- goto out;
- zbud_evict_pages(nr);
- }
- ret = (int)atomic_read(&zcache_zbud_curr_raw_pages);
-out:
- return ret;
-}
-
-static struct shrinker zcache_shrinker = {
- .shrink = shrink_zcache_memory,
- .seeks = DEFAULT_SEEKS,
-};
-
-/*
- * zcache shims between cleancache/frontswap ops and tmem
- */
-
-int zcache_put(int cli_id, int pool_id, struct tmem_oid *oidp,
- uint32_t index, char *data, size_t size,
- bool raw, int ephemeral)
-{
- struct tmem_pool *pool;
- int ret = -1;
-
- BUG_ON(!irqs_disabled());
- pool = zcache_get_pool_by_id(cli_id, pool_id);
- if (unlikely(pool == NULL))
- goto out;
- if (!zcache_freeze && zcache_do_preload(pool) == 0) {
- /* preload does preempt_disable on success */
- ret = tmem_put(pool, oidp, index, data, size, raw, ephemeral);
- if (ret < 0) {
- if (is_ephemeral(pool))
- zcache_failed_eph_puts++;
- else
- zcache_failed_pers_puts++;
- }
- zcache_put_pool(pool);
- preempt_enable_no_resched();
- } else {
- zcache_put_to_flush++;
- if (atomic_read(&pool->obj_count) > 0)
- /* the put fails whether the flush succeeds or not */
- (void)tmem_flush_page(pool, oidp, index);
- zcache_put_pool(pool);
- }
-out:
- return ret;
-}
-
-int zcache_get(int cli_id, int pool_id, struct tmem_oid *oidp,
- uint32_t index, char *data, size_t *sizep,
- bool raw, int get_and_free)
-{
- struct tmem_pool *pool;
- int ret = -1;
- bool eph;
-
- if (!raw) {
- BUG_ON(irqs_disabled());
- BUG_ON(in_softirq());
- }
- pool = zcache_get_pool_by_id(cli_id, pool_id);
- eph = is_ephemeral(pool);
- if (likely(pool != NULL)) {
- if (atomic_read(&pool->obj_count) > 0)
- ret = tmem_get(pool, oidp, index, data, sizep,
- raw, get_and_free);
- zcache_put_pool(pool);
- }
- WARN_ONCE((!eph && (ret != 0)), "zcache_get fails on persistent pool, "
- "bad things are very likely to happen soon\n");
-#ifdef RAMSTER_TESTING
- if (ret != 0 && ret != -1 && !(ret == -EINVAL && is_ephemeral(pool)))
- pr_err("TESTING zcache_get tmem_get returns ret=%d\n", ret);
-#endif
- if (ret == -EAGAIN)
- BUG(); /* FIXME... don't need this anymore??? let's ensure */
- return ret;
-}
-
-int zcache_flush(int cli_id, int pool_id,
- struct tmem_oid *oidp, uint32_t index)
-{
- struct tmem_pool *pool;
- int ret = -1;
- unsigned long flags;
-
- local_irq_save(flags);
- zcache_flush_total++;
- pool = zcache_get_pool_by_id(cli_id, pool_id);
- ramster_do_preload_flnode_only(pool);
- if (likely(pool != NULL)) {
- if (atomic_read(&pool->obj_count) > 0)
- ret = tmem_flush_page(pool, oidp, index);
- zcache_put_pool(pool);
- }
- if (ret >= 0)
- zcache_flush_found++;
- local_irq_restore(flags);
- return ret;
-}
-
-int zcache_flush_object(int cli_id, int pool_id, struct tmem_oid *oidp)
-{
- struct tmem_pool *pool;
- int ret = -1;
- unsigned long flags;
-
- local_irq_save(flags);
- zcache_flobj_total++;
- pool = zcache_get_pool_by_id(cli_id, pool_id);
- ramster_do_preload_flnode_only(pool);
- if (likely(pool != NULL)) {
- if (atomic_read(&pool->obj_count) > 0)
- ret = tmem_flush_object(pool, oidp);
- zcache_put_pool(pool);
- }
- if (ret >= 0)
- zcache_flobj_found++;
- local_irq_restore(flags);
- return ret;
-}
-
-int zcache_client_destroy_pool(int cli_id, int pool_id)
-{
- struct tmem_pool *pool = NULL;
- struct zcache_client *cli = NULL;
- int ret = -1;
-
- if (pool_id < 0)
- goto out;
- if (cli_id == LOCAL_CLIENT)
- cli = &zcache_host;
- else if ((unsigned int)cli_id < MAX_CLIENTS)
- cli = &zcache_clients[cli_id];
- if (cli == NULL)
- goto out;
- atomic_inc(&cli->refcount);
- pool = cli->tmem_pools[pool_id];
- if (pool == NULL)
- goto out;
- cli->tmem_pools[pool_id] = NULL;
- /* wait for pool activity on other cpus to quiesce */
- while (atomic_read(&pool->refcount) != 0)
- ;
- atomic_dec(&cli->refcount);
- local_bh_disable();
- ret = tmem_destroy_pool(pool);
- local_bh_enable();
- kfree(pool);
- pr_info("ramster: destroyed pool id=%d cli_id=%d\n", pool_id, cli_id);
-out:
- return ret;
-}
-
-static int zcache_destroy_pool(int pool_id)
-{
- return zcache_client_destroy_pool(LOCAL_CLIENT, pool_id);
-}
-
-int zcache_new_pool(uint16_t cli_id, uint32_t flags)
-{
- int poolid = -1;
- struct tmem_pool *pool;
- struct zcache_client *cli = NULL;
-
- if (cli_id == LOCAL_CLIENT)
- cli = &zcache_host;
- else if ((unsigned int)cli_id < MAX_CLIENTS)
- cli = &zcache_clients[cli_id];
- if (cli == NULL)
- goto out;
- atomic_inc(&cli->refcount);
- pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC);
- if (pool == NULL) {
- pr_info("ramster: pool creation failed: out of memory\n");
- goto out;
- }
-
- for (poolid = 0; poolid < MAX_POOLS_PER_CLIENT; poolid++)
- if (cli->tmem_pools[poolid] == NULL)
- break;
- if (poolid >= MAX_POOLS_PER_CLIENT) {
- pr_info("ramster: pool creation failed: max exceeded\n");
- kfree(pool);
- poolid = -1;
- goto out;
- }
- atomic_set(&pool->refcount, 0);
- pool->client = cli;
- pool->pool_id = poolid;
- tmem_new_pool(pool, flags);
- cli->tmem_pools[poolid] = pool;
- if (cli_id == LOCAL_CLIENT)
- pr_info("ramster: created %s tmem pool, id=%d, local client\n",
- flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
- poolid);
- else
- pr_info("ramster: created %s tmem pool, id=%d, client=%d\n",
- flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
- poolid, cli_id);
-out:
- if (cli != NULL)
- atomic_dec(&cli->refcount);
- return poolid;
-}
-
-static int zcache_local_new_pool(uint32_t flags)
-{
- return zcache_new_pool(LOCAL_CLIENT, flags);
-}
-
-int zcache_autocreate_pool(int cli_id, int pool_id, bool ephemeral)
-{
- struct tmem_pool *pool;
- struct zcache_client *cli = NULL;
- uint32_t flags = ephemeral ? 0 : TMEM_POOL_PERSIST;
- int ret = -1;
-
- if (cli_id == LOCAL_CLIENT)
- goto out;
- if (pool_id >= MAX_POOLS_PER_CLIENT)
- goto out;
- else if ((unsigned int)cli_id < MAX_CLIENTS)
- cli = &zcache_clients[cli_id];
- if ((ephemeral && !use_cleancache) || (!ephemeral && !use_frontswap))
- BUG(); /* FIXME, handle more gracefully later */
- if (!cli->allocated) {
- if (zcache_new_client(cli_id))
- BUG(); /* FIXME, handle more gracefully later */
- cli = &zcache_clients[cli_id];
- }
- atomic_inc(&cli->refcount);
- pool = cli->tmem_pools[pool_id];
- if (pool != NULL) {
- if (pool->persistent && ephemeral) {
- pr_err("zcache_autocreate_pool: type mismatch\n");
- goto out;
- }
- ret = 0;
- goto out;
- }
- pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL);
- if (pool == NULL) {
- pr_info("ramster: pool creation failed: out of memory\n");
- goto out;
- }
- atomic_set(&pool->refcount, 0);
- pool->client = cli;
- pool->pool_id = pool_id;
- tmem_new_pool(pool, flags);
- cli->tmem_pools[pool_id] = pool;
- pr_info("ramster: AUTOcreated %s tmem poolid=%d, for remote client=%d\n",
- flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
- pool_id, cli_id);
- ret = 0;
-out:
- if (cli == NULL)
- BUG(); /* FIXME, handle more gracefully later */
- /* pr_err("zcache_autocreate_pool: failed\n"); */
- if (cli != NULL)
- atomic_dec(&cli->refcount);
- return ret;
-}
-
-/**********
- * Two kernel functionalities currently can be layered on top of tmem.
- * These are "cleancache" which is used as a second-chance cache for clean
- * page cache pages; and "frontswap" which is used for swap pages
- * to avoid writes to disk. A generic "shim" is provided here for each
- * to translate in-kernel semantics to zcache semantics.
- */
-
-#ifdef CONFIG_CLEANCACHE
-static void zcache_cleancache_put_page(int pool_id,
- struct cleancache_filekey key,
- pgoff_t index, struct page *page)
-{
- u32 ind = (u32) index;
- struct tmem_oid oid = *(struct tmem_oid *)&key;
-
-#ifdef __PG_WAS_ACTIVE
- if (!PageWasActive(page)) {
- zcache_nonactive_puts++;
- return;
- }
-#endif
- if (likely(ind == index)) {
- char *kva = page_address(page);
-
- (void)zcache_put(LOCAL_CLIENT, pool_id, &oid, index,
- kva, PAGE_SIZE, 0, 1);
- }
-}
-
-static int zcache_cleancache_get_page(int pool_id,
- struct cleancache_filekey key,
- pgoff_t index, struct page *page)
-{
- u32 ind = (u32) index;
- struct tmem_oid oid = *(struct tmem_oid *)&key;
- int ret = -1;
-
- preempt_disable();
- if (likely(ind == index)) {
- char *kva = page_address(page);
- size_t size = PAGE_SIZE;
-
- ret = zcache_get(LOCAL_CLIENT, pool_id, &oid, index,
- kva, &size, 0, 0);
-#ifdef __PG_WAS_ACTIVE
- if (ret == 0)
- SetPageWasActive(page);
-#endif
- }
- preempt_enable();
- return ret;
-}
-
-static void zcache_cleancache_flush_page(int pool_id,
- struct cleancache_filekey key,
- pgoff_t index)
-{
- u32 ind = (u32) index;
- struct tmem_oid oid = *(struct tmem_oid *)&key;
-
- if (likely(ind == index))
- (void)zcache_flush(LOCAL_CLIENT, pool_id, &oid, ind);
-}
-
-static void zcache_cleancache_flush_inode(int pool_id,
- struct cleancache_filekey key)
-{
- struct tmem_oid oid = *(struct tmem_oid *)&key;
-
- (void)zcache_flush_object(LOCAL_CLIENT, pool_id, &oid);
-}
-
-static void zcache_cleancache_flush_fs(int pool_id)
-{
- if (pool_id >= 0)
- (void)zcache_destroy_pool(pool_id);
-}
-
-static int zcache_cleancache_init_fs(size_t pagesize)
-{
- BUG_ON(sizeof(struct cleancache_filekey) !=
- sizeof(struct tmem_oid));
- BUG_ON(pagesize != PAGE_SIZE);
- return zcache_local_new_pool(0);
-}
-
-static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize)
-{
- /* shared pools are unsupported and map to private */
- BUG_ON(sizeof(struct cleancache_filekey) !=
- sizeof(struct tmem_oid));
- BUG_ON(pagesize != PAGE_SIZE);
- return zcache_local_new_pool(0);
-}
-
-static struct cleancache_ops zcache_cleancache_ops = {
- .put_page = zcache_cleancache_put_page,
- .get_page = zcache_cleancache_get_page,
- .invalidate_page = zcache_cleancache_flush_page,
- .invalidate_inode = zcache_cleancache_flush_inode,
- .invalidate_fs = zcache_cleancache_flush_fs,
- .init_shared_fs = zcache_cleancache_init_shared_fs,
- .init_fs = zcache_cleancache_init_fs
-};
-
-struct cleancache_ops zcache_cleancache_register_ops(void)
-{
- struct cleancache_ops old_ops =
- cleancache_register_ops(&zcache_cleancache_ops);
-
- return old_ops;
-}
-#endif
-
-#ifdef CONFIG_FRONTSWAP
-/* a single tmem poolid is used for all frontswap "types" (swapfiles) */
-static int zcache_frontswap_poolid = -1;
-
-/*
- * Swizzling increases objects per swaptype, increasing tmem concurrency
- * for heavy swaploads. Later, larger nr_cpus -> larger SWIZ_BITS
- */
-#define SWIZ_BITS 8
-#define SWIZ_MASK ((1 << SWIZ_BITS) - 1)
-#define _oswiz(_type, _ind) ((_type << SWIZ_BITS) | (_ind & SWIZ_MASK))
-#define iswiz(_ind) (_ind >> SWIZ_BITS)
-
-static inline struct tmem_oid oswiz(unsigned type, u32 ind)
-{
- struct tmem_oid oid = { .oid = { 0 } };
- oid.oid[0] = _oswiz(type, ind);
- return oid;
-}
-
-static int zcache_frontswap_store(unsigned type, pgoff_t offset,
- struct page *page)
-{
- u64 ind64 = (u64)offset;
- u32 ind = (u32)offset;
- struct tmem_oid oid = oswiz(type, ind);
- int ret = -1;
- unsigned long flags;
- char *kva;
-
- BUG_ON(!PageLocked(page));
- if (likely(ind64 == ind)) {
- local_irq_save(flags);
- kva = page_address(page);
- ret = zcache_put(LOCAL_CLIENT, zcache_frontswap_poolid,
- &oid, iswiz(ind), kva, PAGE_SIZE, 0, 0);
- local_irq_restore(flags);
- }
- return ret;
-}
-
-/* returns 0 if the page was successfully gotten from frontswap, -1 if
- * was not present (should never happen!) */
-static int zcache_frontswap_load(unsigned type, pgoff_t offset,
- struct page *page)
-{
- u64 ind64 = (u64)offset;
- u32 ind = (u32)offset;
- struct tmem_oid oid = oswiz(type, ind);
- int ret = -1;
-
- preempt_disable(); /* FIXME, remove this? */
- BUG_ON(!PageLocked(page));
- if (likely(ind64 == ind)) {
- char *kva = page_address(page);
- size_t size = PAGE_SIZE;
-
- ret = zcache_get(LOCAL_CLIENT, zcache_frontswap_poolid,
- &oid, iswiz(ind), kva, &size, 0, -1);
- }
- preempt_enable(); /* FIXME, remove this? */
- return ret;
-}
-
-/* flush a single page from frontswap */
-static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset)
-{
- u64 ind64 = (u64)offset;
- u32 ind = (u32)offset;
- struct tmem_oid oid = oswiz(type, ind);
-
- if (likely(ind64 == ind))
- (void)zcache_flush(LOCAL_CLIENT, zcache_frontswap_poolid,
- &oid, iswiz(ind));
-}
-
-/* flush all pages from the passed swaptype */
-static void zcache_frontswap_flush_area(unsigned type)
-{
- struct tmem_oid oid;
- int ind;
-
- for (ind = SWIZ_MASK; ind >= 0; ind--) {
- oid = oswiz(type, ind);
- (void)zcache_flush_object(LOCAL_CLIENT,
- zcache_frontswap_poolid, &oid);
- }
-}
-
-static void zcache_frontswap_init(unsigned ignored)
-{
- /* a single tmem poolid is used for all frontswap "types" (swapfiles) */
- if (zcache_frontswap_poolid < 0)
- zcache_frontswap_poolid =
- zcache_local_new_pool(TMEM_POOL_PERSIST);
-}
-
-static struct frontswap_ops zcache_frontswap_ops = {
- .store = zcache_frontswap_store,
- .load = zcache_frontswap_load,
- .invalidate_page = zcache_frontswap_flush_page,
- .invalidate_area = zcache_frontswap_flush_area,
- .init = zcache_frontswap_init
-};
-
-struct frontswap_ops zcache_frontswap_register_ops(void)
-{
- struct frontswap_ops old_ops =
- frontswap_register_ops(&zcache_frontswap_ops);
-
- return old_ops;
-}
-#endif
-
-/*
- * frontswap selfshrinking
- */
-
-#ifdef CONFIG_FRONTSWAP
-/* In HZ, controls frequency of worker invocation. */
-static unsigned int selfshrink_interval __read_mostly = 5;
-
-static void selfshrink_process(struct work_struct *work);
-static DECLARE_DELAYED_WORK(selfshrink_worker, selfshrink_process);
-
-/* Enable/disable with sysfs. */
-static bool frontswap_selfshrinking __read_mostly;
-
-/* Enable/disable with kernel boot option. */
-static bool use_frontswap_selfshrink __initdata = true;
-
-/*
- * The default values for the following parameters were deemed reasonable
- * by experimentation, may be workload-dependent, and can all be
- * adjusted via sysfs.
- */
-
-/* Control rate for frontswap shrinking. Higher hysteresis is slower. */
-static unsigned int frontswap_hysteresis __read_mostly = 20;
-
-/*
- * Number of selfshrink worker invocations to wait before observing that
- * frontswap selfshrinking should commence. Note that selfshrinking does
- * not use a separate worker thread.
- */
-static unsigned int frontswap_inertia __read_mostly = 3;
-
-/* Countdown to next invocation of frontswap_shrink() */
-static unsigned long frontswap_inertia_counter;
-
-/*
- * Invoked by the selfshrink worker thread, uses current number of pages
- * in frontswap (frontswap_curr_pages()), previous status, and control
- * values (hysteresis and inertia) to determine if frontswap should be
- * shrunk and what the new frontswap size should be. Note that
- * frontswap_shrink is essentially a partial swapoff that immediately
- * transfers pages from the "swap device" (frontswap) back into kernel
- * RAM; despite the name, frontswap "shrinking" is very different from
- * the "shrinker" interface used by the kernel MM subsystem to reclaim
- * memory.
- */
-static void frontswap_selfshrink(void)
-{
- static unsigned long cur_frontswap_pages;
- static unsigned long last_frontswap_pages;
- static unsigned long tgt_frontswap_pages;
-
- last_frontswap_pages = cur_frontswap_pages;
- cur_frontswap_pages = frontswap_curr_pages();
- if (!cur_frontswap_pages ||
- (cur_frontswap_pages > last_frontswap_pages)) {
- frontswap_inertia_counter = frontswap_inertia;
- return;
- }
- if (frontswap_inertia_counter && --frontswap_inertia_counter)
- return;
- if (cur_frontswap_pages <= frontswap_hysteresis)
- tgt_frontswap_pages = 0;
- else
- tgt_frontswap_pages = cur_frontswap_pages -
- (cur_frontswap_pages / frontswap_hysteresis);
- frontswap_shrink(tgt_frontswap_pages);
-}
-
-static int __init ramster_nofrontswap_selfshrink_setup(char *s)
-{
- use_frontswap_selfshrink = false;
- return 1;
-}
-
-__setup("noselfshrink", ramster_nofrontswap_selfshrink_setup);
-
-static void selfshrink_process(struct work_struct *work)
-{
- if (frontswap_selfshrinking && frontswap_enabled) {
- frontswap_selfshrink();
- schedule_delayed_work(&selfshrink_worker,
- selfshrink_interval * HZ);
- }
-}
-
-static int ramster_enabled;
-
-static int __init ramster_selfshrink_init(void)
-{
- frontswap_selfshrinking = ramster_enabled && use_frontswap_selfshrink;
- if (frontswap_selfshrinking)
- pr_info("ramster: Initializing frontswap "
- "selfshrinking driver.\n");
- else
- return -ENODEV;
-
- schedule_delayed_work(&selfshrink_worker, selfshrink_interval * HZ);
-
- return 0;
-}
-
-subsys_initcall(ramster_selfshrink_init);
-#endif
-
-/*
- * zcache initialization
- * NOTE FOR NOW ramster MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR
- * NOTHING HAPPENS!
- */
-
-static int ramster_enabled;
-
-static int __init enable_ramster(char *s)
-{
- ramster_enabled = 1;
- return 1;
-}
-__setup("ramster", enable_ramster);
-
-/* allow independent dynamic disabling of cleancache and frontswap */
-
-static int use_cleancache = 1;
-
-static int __init no_cleancache(char *s)
-{
- pr_info("INIT no_cleancache called\n");
- use_cleancache = 0;
- return 1;
-}
-
-/*
- * FIXME: need to guarantee this gets checked before zcache_init is called
- * What is the correct way to achieve this?
- */
-early_param("nocleancache", no_cleancache);
-
-static int use_frontswap = 1;
-
-static int __init no_frontswap(char *s)
-{
- pr_info("INIT no_frontswap called\n");
- use_frontswap = 0;
- return 1;
-}
-
-__setup("nofrontswap", no_frontswap);
-
-static int __init zcache_init(void)
-{
- int ret = 0;
-
-#ifdef CONFIG_SYSFS
- ret = sysfs_create_group(mm_kobj, &zcache_attr_group);
- ret = sysfs_create_group(mm_kobj, &ramster_attr_group);
- if (ret) {
- pr_err("ramster: can't create sysfs\n");
- goto out;
- }
-#endif /* CONFIG_SYSFS */
-#if defined(CONFIG_CLEANCACHE) || defined(CONFIG_FRONTSWAP)
- if (ramster_enabled) {
- unsigned int cpu;
-
- (void)r2net_register_handlers();
- tmem_register_hostops(&zcache_hostops);
- tmem_register_pamops(&zcache_pamops);
- ret = register_cpu_notifier(&zcache_cpu_notifier_block);
- if (ret) {
- pr_err("ramster: can't register cpu notifier\n");
- goto out;
- }
- for_each_online_cpu(cpu) {
- void *pcpu = (void *)(long)cpu;
- zcache_cpu_notifier(&zcache_cpu_notifier_block,
- CPU_UP_PREPARE, pcpu);
- }
- }
- zcache_objnode_cache = kmem_cache_create("zcache_objnode",
- sizeof(struct tmem_objnode), 0, 0, NULL);
- zcache_obj_cache = kmem_cache_create("zcache_obj",
- sizeof(struct tmem_obj), 0, 0, NULL);
- ramster_flnode_cache = kmem_cache_create("ramster_flnode",
- sizeof(struct flushlist_node), 0, 0, NULL);
-#endif
-#ifdef CONFIG_CLEANCACHE
- pr_info("INIT ramster_enabled=%d use_cleancache=%d\n",
- ramster_enabled, use_cleancache);
- if (ramster_enabled && use_cleancache) {
- struct cleancache_ops old_ops;
-
- zbud_init();
- register_shrinker(&zcache_shrinker);
- old_ops = zcache_cleancache_register_ops();
- pr_info("ramster: cleancache enabled using kernel "
- "transcendent memory and compression buddies\n");
- if (old_ops.init_fs != NULL)
- pr_warning("ramster: cleancache_ops overridden");
- }
-#endif
-#ifdef CONFIG_FRONTSWAP
- pr_info("INIT ramster_enabled=%d use_frontswap=%d\n",
- ramster_enabled, use_frontswap);
- if (ramster_enabled && use_frontswap) {
- struct frontswap_ops old_ops;
-
- zcache_new_client(LOCAL_CLIENT);
- old_ops = zcache_frontswap_register_ops();
- pr_info("ramster: frontswap enabled using kernel "
- "transcendent memory and xvmalloc\n");
- if (old_ops.init != NULL)
- pr_warning("ramster: frontswap_ops overridden");
- }
- if (ramster_enabled && (use_frontswap || use_cleancache))
- ramster_remotify_init();
-#endif
-out:
- return ret;
-}
-
-module_init(zcache_init)