xfs: embedd mru_elem into parent structure
There is no need to do a separate allocation for each mru element, just
embedd the structure into the parent one in the user. Besides saving
a memory allocation and the infrastructure required for it this also
simplifies the API.
While we do major surgery on xfs_mru_cache.c also de-typedef it and
make struct mru_cache private to the implementation file.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_mru_cache.c b/fs/xfs/xfs_mru_cache.c
index 4aa3166..f99b493 100644
--- a/fs/xfs/xfs_mru_cache.c
+++ b/fs/xfs/xfs_mru_cache.c
@@ -100,14 +100,20 @@
* likely result in a loop in one of the lists. That's a sure-fire recipe for
* an infinite loop in the code.
*/
-typedef struct xfs_mru_cache_elem
-{
- struct list_head list_node;
- unsigned long key;
- void *value;
-} xfs_mru_cache_elem_t;
+struct xfs_mru_cache {
+ struct radix_tree_root store; /* Core storage data structure. */
+ struct list_head *lists; /* Array of lists, one per grp. */
+ struct list_head reap_list; /* Elements overdue for reaping. */
+ spinlock_t lock; /* Lock to protect this struct. */
+ unsigned int grp_count; /* Number of discrete groups. */
+ unsigned int grp_time; /* Time period spanned by grps. */
+ unsigned int lru_grp; /* Group containing time zero. */
+ unsigned long time_zero; /* Time first element was added. */
+ xfs_mru_cache_free_func_t free_func; /* Function pointer for freeing. */
+ struct delayed_work work; /* Workqueue data for reaping. */
+ unsigned int queued; /* work has been queued */
+};
-static kmem_zone_t *xfs_mru_elem_zone;
static struct workqueue_struct *xfs_mru_reap_wq;
/*
@@ -129,12 +135,12 @@
*/
STATIC unsigned long
_xfs_mru_cache_migrate(
- xfs_mru_cache_t *mru,
- unsigned long now)
+ struct xfs_mru_cache *mru,
+ unsigned long now)
{
- unsigned int grp;
- unsigned int migrated = 0;
- struct list_head *lru_list;
+ unsigned int grp;
+ unsigned int migrated = 0;
+ struct list_head *lru_list;
/* Nothing to do if the data store is empty. */
if (!mru->time_zero)
@@ -193,11 +199,11 @@
*/
STATIC void
_xfs_mru_cache_list_insert(
- xfs_mru_cache_t *mru,
- xfs_mru_cache_elem_t *elem)
+ struct xfs_mru_cache *mru,
+ struct xfs_mru_cache_elem *elem)
{
- unsigned int grp = 0;
- unsigned long now = jiffies;
+ unsigned int grp = 0;
+ unsigned long now = jiffies;
/*
* If the data store is empty, initialise time zero, leave grp set to
@@ -231,10 +237,10 @@
*/
STATIC void
_xfs_mru_cache_clear_reap_list(
- xfs_mru_cache_t *mru) __releases(mru->lock) __acquires(mru->lock)
-
+ struct xfs_mru_cache *mru)
+ __releases(mru->lock) __acquires(mru->lock)
{
- xfs_mru_cache_elem_t *elem, *next;
+ struct xfs_mru_cache_elem *elem, *next;
struct list_head tmp;
INIT_LIST_HEAD(&tmp);
@@ -252,15 +258,8 @@
spin_unlock(&mru->lock);
list_for_each_entry_safe(elem, next, &tmp, list_node) {
-
- /* Remove the element from the reap list. */
list_del_init(&elem->list_node);
-
- /* Call the client's free function with the key and value pointer. */
- mru->free_func(elem->key, elem->value);
-
- /* Free the element structure. */
- kmem_zone_free(xfs_mru_elem_zone, elem);
+ mru->free_func(elem);
}
spin_lock(&mru->lock);
@@ -277,7 +276,8 @@
_xfs_mru_cache_reap(
struct work_struct *work)
{
- xfs_mru_cache_t *mru = container_of(work, xfs_mru_cache_t, work.work);
+ struct xfs_mru_cache *mru =
+ container_of(work, struct xfs_mru_cache, work.work);
unsigned long now, next;
ASSERT(mru && mru->lists);
@@ -304,28 +304,16 @@
int
xfs_mru_cache_init(void)
{
- xfs_mru_elem_zone = kmem_zone_init(sizeof(xfs_mru_cache_elem_t),
- "xfs_mru_cache_elem");
- if (!xfs_mru_elem_zone)
- goto out;
-
xfs_mru_reap_wq = alloc_workqueue("xfs_mru_cache", WQ_MEM_RECLAIM, 1);
if (!xfs_mru_reap_wq)
- goto out_destroy_mru_elem_zone;
-
+ return -ENOMEM;
return 0;
-
- out_destroy_mru_elem_zone:
- kmem_zone_destroy(xfs_mru_elem_zone);
- out:
- return -ENOMEM;
}
void
xfs_mru_cache_uninit(void)
{
destroy_workqueue(xfs_mru_reap_wq);
- kmem_zone_destroy(xfs_mru_elem_zone);
}
/*
@@ -336,14 +324,14 @@
*/
int
xfs_mru_cache_create(
- xfs_mru_cache_t **mrup,
+ struct xfs_mru_cache **mrup,
unsigned int lifetime_ms,
unsigned int grp_count,
xfs_mru_cache_free_func_t free_func)
{
- xfs_mru_cache_t *mru = NULL;
- int err = 0, grp;
- unsigned int grp_time;
+ struct xfs_mru_cache *mru = NULL;
+ int err = 0, grp;
+ unsigned int grp_time;
if (mrup)
*mrup = NULL;
@@ -400,7 +388,7 @@
*/
static void
xfs_mru_cache_flush(
- xfs_mru_cache_t *mru)
+ struct xfs_mru_cache *mru)
{
if (!mru || !mru->lists)
return;
@@ -420,7 +408,7 @@
void
xfs_mru_cache_destroy(
- xfs_mru_cache_t *mru)
+ struct xfs_mru_cache *mru)
{
if (!mru || !mru->lists)
return;
@@ -438,45 +426,29 @@
*/
int
xfs_mru_cache_insert(
- xfs_mru_cache_t *mru,
- unsigned long key,
- void *value)
+ struct xfs_mru_cache *mru,
+ unsigned long key,
+ struct xfs_mru_cache_elem *elem)
{
- xfs_mru_cache_elem_t *elem;
- int error;
+ int error;
ASSERT(mru && mru->lists);
if (!mru || !mru->lists)
return EINVAL;
- elem = kmem_zone_zalloc(xfs_mru_elem_zone, KM_SLEEP);
- if (!elem)
+ if (radix_tree_preload(GFP_KERNEL))
return ENOMEM;
- if (radix_tree_preload(GFP_KERNEL)) {
- error = ENOMEM;
- goto out_free_item;
- }
-
INIT_LIST_HEAD(&elem->list_node);
elem->key = key;
- elem->value = value;
spin_lock(&mru->lock);
-
error = -radix_tree_insert(&mru->store, key, elem);
radix_tree_preload_end();
- if (error) {
- spin_unlock(&mru->lock);
- goto out_free_item;
- }
- _xfs_mru_cache_list_insert(mru, elem);
-
+ if (!error)
+ _xfs_mru_cache_list_insert(mru, elem);
spin_unlock(&mru->lock);
- return 0;
-out_free_item:
- kmem_zone_free(xfs_mru_elem_zone, elem);
return error;
}
@@ -486,13 +458,12 @@
* the client data pointer for the removed element is returned, otherwise this
* function will return a NULL pointer.
*/
-void *
+struct xfs_mru_cache_elem *
xfs_mru_cache_remove(
- xfs_mru_cache_t *mru,
- unsigned long key)
+ struct xfs_mru_cache *mru,
+ unsigned long key)
{
- xfs_mru_cache_elem_t *elem;
- void *value = NULL;
+ struct xfs_mru_cache_elem *elem;
ASSERT(mru && mru->lists);
if (!mru || !mru->lists)
@@ -500,17 +471,11 @@
spin_lock(&mru->lock);
elem = radix_tree_delete(&mru->store, key);
- if (elem) {
- value = elem->value;
+ if (elem)
list_del(&elem->list_node);
- }
-
spin_unlock(&mru->lock);
- if (elem)
- kmem_zone_free(xfs_mru_elem_zone, elem);
-
- return value;
+ return elem;
}
/*
@@ -519,13 +484,14 @@
*/
void
xfs_mru_cache_delete(
- xfs_mru_cache_t *mru,
- unsigned long key)
+ struct xfs_mru_cache *mru,
+ unsigned long key)
{
- void *value = xfs_mru_cache_remove(mru, key);
+ struct xfs_mru_cache_elem *elem;
- if (value)
- mru->free_func(key, value);
+ elem = xfs_mru_cache_remove(mru, key);
+ if (elem)
+ mru->free_func(elem);
}
/*
@@ -548,12 +514,12 @@
* status, we need to help it get it right by annotating the path that does
* not release the lock.
*/
-void *
+struct xfs_mru_cache_elem *
xfs_mru_cache_lookup(
- xfs_mru_cache_t *mru,
- unsigned long key)
+ struct xfs_mru_cache *mru,
+ unsigned long key)
{
- xfs_mru_cache_elem_t *elem;
+ struct xfs_mru_cache_elem *elem;
ASSERT(mru && mru->lists);
if (!mru || !mru->lists)
@@ -568,7 +534,7 @@
} else
spin_unlock(&mru->lock);
- return elem ? elem->value : NULL;
+ return elem;
}
/*
@@ -578,7 +544,8 @@
*/
void
xfs_mru_cache_done(
- xfs_mru_cache_t *mru) __releases(mru->lock)
+ struct xfs_mru_cache *mru)
+ __releases(mru->lock)
{
spin_unlock(&mru->lock);
}