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authorBob Peterson <rpeterso@redhat.com>2011-10-26 15:24:55 -0500
committerDavid Teigland <teigland@redhat.com>2011-11-18 10:20:15 -0600
commit9beb3bf5a92bb8fc6503f844bf0772df29f14a02 (patch)
treec60963c27d0a93ae1f572e6fda9c090a4a702d4e /fs/dlm/lock.c
parentc3b92c8787367a8bb53d57d9789b558f1295cc96 (diff)
downloadlinux-linaro-stable-9beb3bf5a92bb8fc6503f844bf0772df29f14a02.tar.gz
dlm: convert rsb list to rb_tree
Change the linked lists to rb_tree's in the rsb hash table to speed up searches. Slow rsb searches were having a large impact on gfs2 performance due to the large number of dlm locks gfs2 uses. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
Diffstat (limited to 'fs/dlm/lock.c')
-rw-r--r--fs/dlm/lock.c87
1 files changed, 70 insertions, 17 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 83b5e32514e1..d47183043c59 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -56,6 +56,7 @@
L: receive_xxxx_reply() <- R: send_xxxx_reply()
*/
#include <linux/types.h>
+#include <linux/rbtree.h>
#include <linux/slab.h>
#include "dlm_internal.h"
#include <linux/dlm_device.h>
@@ -380,6 +381,8 @@ static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
r = list_first_entry(&ls->ls_new_rsb, struct dlm_rsb, res_hashchain);
list_del(&r->res_hashchain);
+ /* Convert the empty list_head to a NULL rb_node for tree usage: */
+ memset(&r->res_hashnode, 0, sizeof(struct rb_node));
ls->ls_new_rsb_count--;
spin_unlock(&ls->ls_new_rsb_spin);
@@ -388,7 +391,6 @@ static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
memcpy(r->res_name, name, len);
mutex_init(&r->res_mutex);
- INIT_LIST_HEAD(&r->res_hashchain);
INIT_LIST_HEAD(&r->res_lookup);
INIT_LIST_HEAD(&r->res_grantqueue);
INIT_LIST_HEAD(&r->res_convertqueue);
@@ -400,14 +402,31 @@ static int get_rsb_struct(struct dlm_ls *ls, char *name, int len,
return 0;
}
-static int search_rsb_list(struct list_head *head, char *name, int len,
+static int rsb_cmp(struct dlm_rsb *r, const char *name, int nlen)
+{
+ char maxname[DLM_RESNAME_MAXLEN];
+
+ memset(maxname, 0, DLM_RESNAME_MAXLEN);
+ memcpy(maxname, name, nlen);
+ return memcmp(r->res_name, maxname, DLM_RESNAME_MAXLEN);
+}
+
+static int search_rsb_tree(struct rb_root *tree, char *name, int len,
unsigned int flags, struct dlm_rsb **r_ret)
{
+ struct rb_node *node = tree->rb_node;
struct dlm_rsb *r;
int error = 0;
-
- list_for_each_entry(r, head, res_hashchain) {
- if (len == r->res_length && !memcmp(name, r->res_name, len))
+ int rc;
+
+ while (node) {
+ r = rb_entry(node, struct dlm_rsb, res_hashnode);
+ rc = rsb_cmp(r, name, len);
+ if (rc < 0)
+ node = node->rb_left;
+ else if (rc > 0)
+ node = node->rb_right;
+ else
goto found;
}
*r_ret = NULL;
@@ -420,22 +439,54 @@ static int search_rsb_list(struct list_head *head, char *name, int len,
return error;
}
+static int rsb_insert(struct dlm_rsb *rsb, struct rb_root *tree)
+{
+ struct rb_node **newn = &tree->rb_node;
+ struct rb_node *parent = NULL;
+ int rc;
+
+ while (*newn) {
+ struct dlm_rsb *cur = rb_entry(*newn, struct dlm_rsb,
+ res_hashnode);
+
+ parent = *newn;
+ rc = rsb_cmp(cur, rsb->res_name, rsb->res_length);
+ if (rc < 0)
+ newn = &parent->rb_left;
+ else if (rc > 0)
+ newn = &parent->rb_right;
+ else {
+ log_print("rsb_insert match");
+ dlm_dump_rsb(rsb);
+ dlm_dump_rsb(cur);
+ return -EEXIST;
+ }
+ }
+
+ rb_link_node(&rsb->res_hashnode, parent, newn);
+ rb_insert_color(&rsb->res_hashnode, tree);
+ return 0;
+}
+
static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b,
unsigned int flags, struct dlm_rsb **r_ret)
{
struct dlm_rsb *r;
int error;
- error = search_rsb_list(&ls->ls_rsbtbl[b].list, name, len, flags, &r);
+ error = search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, flags, &r);
if (!error) {
kref_get(&r->res_ref);
goto out;
}
- error = search_rsb_list(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
+ error = search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, flags, &r);
if (error)
goto out;
- list_move(&r->res_hashchain, &ls->ls_rsbtbl[b].list);
+ rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
+ error = rsb_insert(r, &ls->ls_rsbtbl[b].keep);
+ if (error)
+ return error;
if (dlm_no_directory(ls))
goto out;
@@ -527,8 +578,7 @@ static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
nodeid = 0;
r->res_nodeid = nodeid;
}
- list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
- error = 0;
+ error = rsb_insert(r, &ls->ls_rsbtbl[bucket].keep);
out_unlock:
spin_unlock(&ls->ls_rsbtbl[bucket].lock);
out:
@@ -556,7 +606,8 @@ static void toss_rsb(struct kref *kref)
DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););
kref_init(&r->res_ref);
- list_move(&r->res_hashchain, &ls->ls_rsbtbl[r->res_bucket].toss);
+ rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[r->res_bucket].keep);
+ rsb_insert(r, &ls->ls_rsbtbl[r->res_bucket].toss);
r->res_toss_time = jiffies;
if (r->res_lvbptr) {
dlm_free_lvb(r->res_lvbptr);
@@ -1082,19 +1133,19 @@ static void dir_remove(struct dlm_rsb *r)
r->res_name, r->res_length);
}
-/* FIXME: shouldn't this be able to exit as soon as one non-due rsb is
- found since they are in order of newest to oldest? */
+/* FIXME: make this more efficient */
static int shrink_bucket(struct dlm_ls *ls, int b)
{
+ struct rb_node *n;
struct dlm_rsb *r;
int count = 0, found;
for (;;) {
found = 0;
spin_lock(&ls->ls_rsbtbl[b].lock);
- list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
- res_hashchain) {
+ for (n = rb_first(&ls->ls_rsbtbl[b].toss); n; n = rb_next(n)) {
+ r = rb_entry(n, struct dlm_rsb, res_hashnode);
if (!time_after_eq(jiffies, r->res_toss_time +
dlm_config.ci_toss_secs * HZ))
continue;
@@ -1108,7 +1159,7 @@ static int shrink_bucket(struct dlm_ls *ls, int b)
}
if (kref_put(&r->res_ref, kill_rsb)) {
- list_del(&r->res_hashchain);
+ rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss);
spin_unlock(&ls->ls_rsbtbl[b].lock);
if (is_master(r))
@@ -4441,10 +4492,12 @@ int dlm_purge_locks(struct dlm_ls *ls)
static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
{
+ struct rb_node *n;
struct dlm_rsb *r, *r_ret = NULL;
spin_lock(&ls->ls_rsbtbl[bucket].lock);
- list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
+ for (n = rb_first(&ls->ls_rsbtbl[bucket].keep); n; n = rb_next(n)) {
+ r = rb_entry(n, struct dlm_rsb, res_hashnode);
if (!rsb_flag(r, RSB_LOCKS_PURGED))
continue;
hold_rsb(r);