lkml.org 
[lkml]   [2013]   [Aug]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 1/2] mbcache: decoupling the locking of local from global data
Date
The patch increases the parallelism of mb_cache_entry utilization by
introducing new spinlocks to the mb_cache structure to protect the mb_cache
local block and index hash chains, while the global mb_cache_lru_list and
mb_cache_list continue to be protected by the global mb_cache_spinlock.

Signed-off-by: T. Makphaibulchoke <tmac@hp.com>
---
Changed in v2:
- As per Linus Torvalds' suggestion, instead of allocating spinlock
arrays to protect the hash chains, use hlist_bl_head, which already
contains builtin lock.

fs/mbcache.c | 293 +++++++++++++++++++++++++++++++++++-------------
include/linux/mbcache.h | 10 +-
2 files changed, 221 insertions(+), 82 deletions(-)

diff --git a/fs/mbcache.c b/fs/mbcache.c
index 8c32ef3..cd4446e 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -26,6 +26,16 @@
* back on the lru list.
*/

+/* Locking protocol:
+ *
+ * The nth hash chain of both the c_block_hash and c_index_hash are
+ * protected by the mth entry of the c_bdev_locks and c_key_locks respectively,
+ * where m is equal to n & c_lock_mask.
+ *
+ * While holding a c_bdev_locks, a thread can acquire either a c_key_locks
+ * or mb_cache_spinlock.
+ */
+
#include <linux/kernel.h>
#include <linux/module.h>

@@ -35,9 +45,9 @@
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/init.h>
+#include <linux/list_bl.h>
#include <linux/mbcache.h>

-
#ifdef MB_CACHE_DEBUG
# define mb_debug(f...) do { \
printk(KERN_DEBUG f); \
@@ -57,6 +67,40 @@

#define MB_CACHE_WRITER ((unsigned short)~0U >> 1)

+#define MB_LOCK_HASH_CHAIN(hash_head) hlist_bl_lock(hash_head)
+#define MB_UNLOCK_HASH_CHAIN(hash_head) hlist_bl_unlock(hash_head)
+#ifdef MB_CACHE_DEBUG
+#define MB_LOCK_BLOCK_HASH(ce) do { \
+ struct hlist_bl_head *block_hash_p = ce->e_block_hash_p;\
+ MB_LOCK_HASH_CHAIN(block_hash_p); \
+ mb_assert(ce->e_block_hash_p == block_hash_p); \
+ } while (0)
+#else
+#define MB_LOCK_BLOCK_HASH(ce) MB_LOCK_HASH_CHAIN(ce->e_block_hash_p)
+#endif
+#define MB_UNLOCK_BLOCK_HASH(ce) MB_UNLOCK_HASH_CHAIN(ce->e_block_hash_p)
+#define MB_LOCK_INDEX_HASH(ce) MB_LOCK_HASH_CHAIN(ce->e_index_hash_p)
+#define MB_UNLOCK_INDEX_HASH(ce) MB_UNLOCK_HASH_CHAIN(ce->e_index_hash_p)
+
+#define MAX_LOCK_RETRY 1024
+
+static inline int __mb_cache_lock_entry_block_hash(struct mb_cache_entry *ce)
+{
+ int nretry = 0;
+ struct hlist_bl_head *block_hash_p = ce->e_block_hash_p;
+
+ do {
+ MB_LOCK_HASH_CHAIN(block_hash_p);
+ if (ce->e_block_hash_p == block_hash_p)
+ return 0;
+ MB_UNLOCK_HASH_CHAIN(block_hash_p);
+ block_hash_p = ce->e_block_hash_p;
+ } while (++nretry < MAX_LOCK_RETRY);
+ return -1;
+}
+
+#define MB_LOCK_ENTRY_BLOCK_HASH(ce) __mb_cache_lock_entry_block_hash(ce)
+
static DECLARE_WAIT_QUEUE_HEAD(mb_cache_queue);

MODULE_AUTHOR("Andreas Gruenbacher <a.gruenbacher@computer.org>");
@@ -101,7 +145,7 @@ static struct shrinker mb_cache_shrinker = {
static inline int
__mb_cache_entry_is_hashed(struct mb_cache_entry *ce)
{
- return !list_empty(&ce->e_block_list);
+ return !hlist_bl_unhashed(&ce->e_block_list);
}


@@ -109,11 +153,26 @@ static void
__mb_cache_entry_unhash(struct mb_cache_entry *ce)
{
if (__mb_cache_entry_is_hashed(ce)) {
- list_del_init(&ce->e_block_list);
- list_del(&ce->e_index.o_list);
+ hlist_bl_del_init(&ce->e_block_list);
+ MB_LOCK_INDEX_HASH(ce);
+ hlist_bl_del(&ce->e_index.o_list);
+ MB_UNLOCK_INDEX_HASH(ce);
}
}

+#ifdef MAK_SRC
+static void
+__mb_cache_entry_unhash_nolock(struct mb_cache_entry *ce)
+{
+ mb_assert(!__mb_cache_entry_is_hashed(ce));
+ mb_assert(!ce->e_block_hash_p);
+ mb_assert(!ce->e_index_hash_p);
+
+ hlist_bl_del_init(&ce->e_block_list);
+ hlist_bl_del(&ce->e_index.o_list);
+}
+#endif /* MAK_SRC */
+

static void
__mb_cache_entry_forget(struct mb_cache_entry *ce, gfp_t gfp_mask)
@@ -127,9 +186,10 @@ __mb_cache_entry_forget(struct mb_cache_entry *ce, gfp_t gfp_mask)


static void
-__mb_cache_entry_release_unlock(struct mb_cache_entry *ce)
- __releases(mb_cache_spinlock)
+__mb_cache_entry_release_unlock(struct mb_cache_entry *ce,
+ struct hlist_bl_head *hash_p)
{
+ mb_assert(hash_p);
/* Wake up all processes queuing for this cache entry. */
if (ce->e_queued)
wake_up_all(&mb_cache_queue);
@@ -139,13 +199,17 @@ __mb_cache_entry_release_unlock(struct mb_cache_entry *ce)
if (!(ce->e_used || ce->e_queued)) {
if (!__mb_cache_entry_is_hashed(ce))
goto forget;
- mb_assert(list_empty(&ce->e_lru_list));
- list_add_tail(&ce->e_lru_list, &mb_cache_lru_list);
- }
- spin_unlock(&mb_cache_spinlock);
+ MB_UNLOCK_HASH_CHAIN(hash_p);
+ spin_lock(&mb_cache_spinlock);
+ if (list_empty(&ce->e_lru_list))
+ list_add_tail(&ce->e_lru_list, &mb_cache_lru_list);
+ spin_unlock(&mb_cache_spinlock);
+ } else
+ MB_UNLOCK_HASH_CHAIN(hash_p);
return;
forget:
- spin_unlock(&mb_cache_spinlock);
+ MB_UNLOCK_HASH_CHAIN(hash_p);
+ mb_assert(list_empty(&ce->e_lru_list));
__mb_cache_entry_forget(ce, GFP_KERNEL);
}

@@ -164,31 +228,45 @@ forget:
static int
mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
{
- LIST_HEAD(free_list);
struct mb_cache *cache;
- struct mb_cache_entry *entry, *tmp;
int count = 0;
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
+ int max_loop = nr_to_scan << 1;

mb_debug("trying to free %d entries", nr_to_scan);
- spin_lock(&mb_cache_spinlock);
- while (nr_to_scan-- && !list_empty(&mb_cache_lru_list)) {
- struct mb_cache_entry *ce =
- list_entry(mb_cache_lru_list.next,
- struct mb_cache_entry, e_lru_list);
- list_move_tail(&ce->e_lru_list, &free_list);
+ while ((nr_to_scan-- > 0) && (max_loop-- > 0)) {
+ struct mb_cache_entry *ce;
+
+ spin_lock(&mb_cache_spinlock);
+ if (list_empty(&mb_cache_lru_list)) {
+ spin_unlock(&mb_cache_spinlock);
+ break;
+ }
+ ce = list_entry(mb_cache_lru_list.next,
+ struct mb_cache_entry, e_lru_list);
+ list_del_init(&ce->e_lru_list);
+ spin_unlock(&mb_cache_spinlock);
+
+ if (MB_LOCK_ENTRY_BLOCK_HASH(ce)) {
+ spin_lock(&mb_cache_spinlock);
+ list_add_tail(&ce->e_lru_list, &mb_cache_lru_list);
+ spin_unlock(&mb_cache_spinlock);
+ continue;
+ }
+ mb_assert(!(ce->e_used || ce->e_queued));
__mb_cache_entry_unhash(ce);
+ MB_UNLOCK_BLOCK_HASH(ce);
+ __mb_cache_entry_forget(ce, gfp_mask);
+ nr_to_scan--;
}
+ spin_lock(&mb_cache_spinlock);
list_for_each_entry(cache, &mb_cache_list, c_cache_list) {
mb_debug("cache %s (%d)", cache->c_name,
atomic_read(&cache->c_entry_count));
count += atomic_read(&cache->c_entry_count);
}
spin_unlock(&mb_cache_spinlock);
- list_for_each_entry_safe(entry, tmp, &free_list, e_lru_list) {
- __mb_cache_entry_forget(entry, gfp_mask);
- }
return (count / 100) * sysctl_vfs_cache_pressure;
}

@@ -216,18 +294,18 @@ mb_cache_create(const char *name, int bucket_bits)
cache->c_name = name;
atomic_set(&cache->c_entry_count, 0);
cache->c_bucket_bits = bucket_bits;
- cache->c_block_hash = kmalloc(bucket_count * sizeof(struct list_head),
- GFP_KERNEL);
+ cache->c_block_hash = kmalloc(bucket_count *
+ sizeof(struct hlist_bl_head), GFP_KERNEL);
if (!cache->c_block_hash)
goto fail;
for (n=0; n<bucket_count; n++)
- INIT_LIST_HEAD(&cache->c_block_hash[n]);
- cache->c_index_hash = kmalloc(bucket_count * sizeof(struct list_head),
- GFP_KERNEL);
+ INIT_HLIST_BL_HEAD(&cache->c_block_hash[n]);
+ cache->c_index_hash = kmalloc(bucket_count *
+ sizeof(struct hlist_bl_head), GFP_KERNEL);
if (!cache->c_index_hash)
goto fail;
for (n=0; n<bucket_count; n++)
- INIT_LIST_HEAD(&cache->c_index_hash[n]);
+ INIT_HLIST_BL_HEAD(&cache->c_index_hash[n]);
cache->c_entry_cache = kmem_cache_create(name,
sizeof(struct mb_cache_entry), 0,
SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
@@ -276,13 +354,22 @@ mb_cache_shrink(struct block_device *bdev)
list_entry(l, struct mb_cache_entry, e_lru_list);
if (ce->e_bdev == bdev) {
list_move_tail(&ce->e_lru_list, &free_list);
- __mb_cache_entry_unhash(ce);
}
}
spin_unlock(&mb_cache_spinlock);
list_for_each_safe(l, ltmp, &free_list) {
- __mb_cache_entry_forget(list_entry(l, struct mb_cache_entry,
- e_lru_list), GFP_KERNEL);
+ struct mb_cache_entry *ce =
+ list_entry(l, struct mb_cache_entry, e_lru_list);
+ if (MB_LOCK_ENTRY_BLOCK_HASH(ce)) {
+ spin_lock(&mb_cache_spinlock);
+ list_add_tail(&ce->e_lru_list, &mb_cache_lru_list);
+ spin_unlock(&mb_cache_spinlock);
+ continue;
+ }
+ mb_assert(!ce->e_used && !ce->e_queued);
+ __mb_cache_entry_unhash(ce);
+ MB_UNLOCK_BLOCK_HASH(ce);
+ __mb_cache_entry_forget(ce, GFP_KERNEL);
}
}

@@ -306,15 +393,18 @@ mb_cache_destroy(struct mb_cache *cache)
list_entry(l, struct mb_cache_entry, e_lru_list);
if (ce->e_cache == cache) {
list_move_tail(&ce->e_lru_list, &free_list);
- __mb_cache_entry_unhash(ce);
}
}
list_del(&cache->c_cache_list);
spin_unlock(&mb_cache_spinlock);

list_for_each_safe(l, ltmp, &free_list) {
- __mb_cache_entry_forget(list_entry(l, struct mb_cache_entry,
- e_lru_list), GFP_KERNEL);
+ struct mb_cache_entry *ce =
+ list_entry(l, struct mb_cache_entry, e_lru_list);
+ MB_LOCK_BLOCK_HASH(ce);
+ __mb_cache_entry_unhash(ce);
+ MB_UNLOCK_BLOCK_HASH(ce);
+ __mb_cache_entry_forget(ce, GFP_KERNEL);
}

if (atomic_read(&cache->c_entry_count) > 0) {
@@ -344,12 +434,26 @@ mb_cache_entry_alloc(struct mb_cache *cache, gfp_t gfp_flags)
struct mb_cache_entry *ce = NULL;

if (atomic_read(&cache->c_entry_count) >= cache->c_max_entries) {
+ struct list_head *l;
+ struct list_head *ltmp;
+
spin_lock(&mb_cache_spinlock);
- if (!list_empty(&mb_cache_lru_list)) {
- ce = list_entry(mb_cache_lru_list.next,
- struct mb_cache_entry, e_lru_list);
- list_del_init(&ce->e_lru_list);
- __mb_cache_entry_unhash(ce);
+ list_for_each_safe(l, ltmp, &mb_cache_lru_list) {
+ ce = list_entry(l, struct mb_cache_entry, e_lru_list);
+ if (ce->e_cache == cache) {
+ list_del_init(&ce->e_lru_list);
+ spin_unlock(&mb_cache_spinlock);
+ if (MB_LOCK_ENTRY_BLOCK_HASH(ce)) {
+ spin_lock(&mb_cache_spinlock);
+ list_add_tail(&ce->e_lru_list,
+ &mb_cache_lru_list);
+ continue;
+ }
+ mb_assert(!ce->e_used && !ce->e_queued);
+ __mb_cache_entry_unhash(ce);
+ MB_UNLOCK_BLOCK_HASH(ce);
+ break;
+ }
}
spin_unlock(&mb_cache_spinlock);
}
@@ -359,9 +463,12 @@ mb_cache_entry_alloc(struct mb_cache *cache, gfp_t gfp_flags)
return NULL;
atomic_inc(&cache->c_entry_count);
INIT_LIST_HEAD(&ce->e_lru_list);
- INIT_LIST_HEAD(&ce->e_block_list);
+ INIT_HLIST_BL_NODE(&ce->e_block_list);
+ INIT_HLIST_BL_NODE(&ce->e_index.o_list);
ce->e_cache = cache;
ce->e_queued = 0;
+ ce->e_block_hash_p = &cache->c_block_hash[0];
+ ce->e_index_hash_p = &cache->c_index_hash[0];
}
ce->e_used = 1 + MB_CACHE_WRITER;
return ce;
@@ -388,28 +495,36 @@ mb_cache_entry_insert(struct mb_cache_entry *ce, struct block_device *bdev,
{
struct mb_cache *cache = ce->e_cache;
unsigned int bucket;
- struct list_head *l;
+ struct hlist_bl_node *l;
int error = -EBUSY;
+ struct hlist_bl_head *block_hash_p;
+ struct hlist_bl_head *index_hash_p;
+ struct mb_cache_entry *lce;

bucket = hash_long((unsigned long)bdev + (block & 0xffffffff),
cache->c_bucket_bits);
- spin_lock(&mb_cache_spinlock);
- list_for_each_prev(l, &cache->c_block_hash[bucket]) {
- struct mb_cache_entry *ce =
- list_entry(l, struct mb_cache_entry, e_block_list);
- if (ce->e_bdev == bdev && ce->e_block == block)
+ block_hash_p = &cache->c_block_hash[bucket];
+ MB_LOCK_HASH_CHAIN(block_hash_p);
+ hlist_bl_for_each_entry(lce, l, block_hash_p, e_block_list) {
+ if (lce->e_bdev == bdev && lce->e_block == block)
goto out;
}
+ mb_assert(!__mb_cache_entry_is_hashed(ce));
__mb_cache_entry_unhash(ce);
ce->e_bdev = bdev;
ce->e_block = block;
- list_add(&ce->e_block_list, &cache->c_block_hash[bucket]);
+ hlist_bl_add_head(&ce->e_block_list, block_hash_p);
+ ce->e_block_hash_p = block_hash_p;
ce->e_index.o_key = key;
bucket = hash_long(key, cache->c_bucket_bits);
- list_add(&ce->e_index.o_list, &cache->c_index_hash[bucket]);
+ index_hash_p = &cache->c_index_hash[bucket];
+ MB_LOCK_HASH_CHAIN(index_hash_p);
+ hlist_bl_add_head(&ce->e_index.o_list, index_hash_p);
+ ce->e_index_hash_p = index_hash_p;
+ MB_UNLOCK_HASH_CHAIN(index_hash_p);
error = 0;
out:
- spin_unlock(&mb_cache_spinlock);
+ MB_UNLOCK_HASH_CHAIN(block_hash_p);
return error;
}

@@ -424,8 +539,8 @@ out:
void
mb_cache_entry_release(struct mb_cache_entry *ce)
{
- spin_lock(&mb_cache_spinlock);
- __mb_cache_entry_release_unlock(ce);
+ MB_LOCK_BLOCK_HASH(ce);
+ __mb_cache_entry_release_unlock(ce, ce->e_block_hash_p);
}


@@ -438,10 +553,12 @@ mb_cache_entry_release(struct mb_cache_entry *ce)
void
mb_cache_entry_free(struct mb_cache_entry *ce)
{
- spin_lock(&mb_cache_spinlock);
+ mb_assert(ce);
+ mb_assert(ce->e_block_hash_p);
+ MB_LOCK_BLOCK_HASH(ce);
mb_assert(list_empty(&ce->e_lru_list));
__mb_cache_entry_unhash(ce);
- __mb_cache_entry_release_unlock(ce);
+ __mb_cache_entry_release_unlock(ce, ce->e_block_hash_p);
}


@@ -458,34 +575,39 @@ mb_cache_entry_get(struct mb_cache *cache, struct block_device *bdev,
sector_t block)
{
unsigned int bucket;
- struct list_head *l;
+ struct hlist_bl_node *l;
struct mb_cache_entry *ce;
+ struct hlist_bl_head *block_hash_p;

bucket = hash_long((unsigned long)bdev + (block & 0xffffffff),
cache->c_bucket_bits);
- spin_lock(&mb_cache_spinlock);
- list_for_each(l, &cache->c_block_hash[bucket]) {
- ce = list_entry(l, struct mb_cache_entry, e_block_list);
+ block_hash_p = &cache->c_block_hash[bucket];
+ MB_LOCK_HASH_CHAIN(block_hash_p);
+ hlist_bl_for_each_entry(ce, l, block_hash_p, e_block_list) {
+ mb_assert(ce->e_block_hash_p == block_hash_p);
if (ce->e_bdev == bdev && ce->e_block == block) {
DEFINE_WAIT(wait);

+ spin_lock(&mb_cache_spinlock);
if (!list_empty(&ce->e_lru_list))
list_del_init(&ce->e_lru_list);
+ spin_unlock(&mb_cache_spinlock);

while (ce->e_used > 0) {
ce->e_queued++;
prepare_to_wait(&mb_cache_queue, &wait,
TASK_UNINTERRUPTIBLE);
- spin_unlock(&mb_cache_spinlock);
+ MB_UNLOCK_BLOCK_HASH(ce);
schedule();
- spin_lock(&mb_cache_spinlock);
+ MB_LOCK_BLOCK_HASH(ce);
ce->e_queued--;
}
finish_wait(&mb_cache_queue, &wait);
ce->e_used += 1 + MB_CACHE_WRITER;

if (!__mb_cache_entry_is_hashed(ce)) {
- __mb_cache_entry_release_unlock(ce);
+ __mb_cache_entry_release_unlock(ce,
+ block_hash_p);
return NULL;
}
goto cleanup;
@@ -494,25 +616,30 @@ mb_cache_entry_get(struct mb_cache *cache, struct block_device *bdev,
ce = NULL;

cleanup:
- spin_unlock(&mb_cache_spinlock);
+ MB_UNLOCK_HASH_CHAIN(block_hash_p);
return ce;
}

#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0)

static struct mb_cache_entry *
-__mb_cache_entry_find(struct list_head *l, struct list_head *head,
+__mb_cache_entry_find(struct hlist_bl_node *l, struct hlist_bl_head *head,
struct block_device *bdev, unsigned int key)
{
- while (l != head) {
+ while (l != NULL) {
struct mb_cache_entry *ce =
- list_entry(l, struct mb_cache_entry, e_index.o_list);
+ hlist_bl_entry(l, struct mb_cache_entry,
+ e_index.o_list);
if (ce->e_bdev == bdev && ce->e_index.o_key == key) {
DEFINE_WAIT(wait);

+ MB_UNLOCK_HASH_CHAIN(head);
+ spin_lock(&mb_cache_spinlock);
if (!list_empty(&ce->e_lru_list))
list_del_init(&ce->e_lru_list);
+ spin_unlock(&mb_cache_spinlock);

+ MB_LOCK_HASH_CHAIN(head);
/* Incrementing before holding the lock gives readers
priority over writers. */
ce->e_used++;
@@ -520,18 +647,20 @@ __mb_cache_entry_find(struct list_head *l, struct list_head *head,
ce->e_queued++;
prepare_to_wait(&mb_cache_queue, &wait,
TASK_UNINTERRUPTIBLE);
- spin_unlock(&mb_cache_spinlock);
+ MB_UNLOCK_HASH_CHAIN(head);
schedule();
- spin_lock(&mb_cache_spinlock);
+ MB_LOCK_HASH_CHAIN(head);
+ mb_assert(ce->e_index_hash_p == head);
ce->e_queued--;
}
finish_wait(&mb_cache_queue, &wait);

if (!__mb_cache_entry_is_hashed(ce)) {
- __mb_cache_entry_release_unlock(ce);
- spin_lock(&mb_cache_spinlock);
+ __mb_cache_entry_release_unlock(ce, head);
+ MB_LOCK_HASH_CHAIN(head);
return ERR_PTR(-EAGAIN);
}
+ mb_assert(ce->e_index_hash_p == head);
return ce;
}
l = l->next;
@@ -557,13 +686,17 @@ mb_cache_entry_find_first(struct mb_cache *cache, struct block_device *bdev,
unsigned int key)
{
unsigned int bucket = hash_long(key, cache->c_bucket_bits);
- struct list_head *l;
- struct mb_cache_entry *ce;
+ struct hlist_bl_node *l;
+ struct mb_cache_entry *ce = NULL;
+ struct hlist_bl_head *index_hash_p;

- spin_lock(&mb_cache_spinlock);
- l = cache->c_index_hash[bucket].next;
- ce = __mb_cache_entry_find(l, &cache->c_index_hash[bucket], bdev, key);
- spin_unlock(&mb_cache_spinlock);
+ index_hash_p = &cache->c_index_hash[bucket];
+ MB_LOCK_HASH_CHAIN(index_hash_p);
+ if (!hlist_bl_empty(index_hash_p)) {
+ l = hlist_bl_first(index_hash_p);
+ ce = __mb_cache_entry_find(l, index_hash_p, bdev, key);
+ }
+ MB_UNLOCK_HASH_CHAIN(index_hash_p);
return ce;
}

@@ -592,13 +725,17 @@ mb_cache_entry_find_next(struct mb_cache_entry *prev,
{
struct mb_cache *cache = prev->e_cache;
unsigned int bucket = hash_long(key, cache->c_bucket_bits);
- struct list_head *l;
+ struct hlist_bl_node *l;
struct mb_cache_entry *ce;
+ struct hlist_bl_head *index_hash_p;

- spin_lock(&mb_cache_spinlock);
+ index_hash_p = &cache->c_index_hash[bucket];
+ mb_assert(prev->e_index_hash_p == index_hash_p);
+ MB_LOCK_HASH_CHAIN(index_hash_p);
+ mb_assert(!hlist_bl_empty(index_hash_p));
l = prev->e_index.o_list.next;
- ce = __mb_cache_entry_find(l, &cache->c_index_hash[bucket], bdev, key);
- __mb_cache_entry_release_unlock(prev);
+ ce = __mb_cache_entry_find(l, index_hash_p, bdev, key);
+ MB_UNLOCK_HASH_CHAIN(index_hash_p);
return ce;
}

diff --git a/include/linux/mbcache.h b/include/linux/mbcache.h
index 5525d37..89826c0 100644
--- a/include/linux/mbcache.h
+++ b/include/linux/mbcache.h
@@ -11,11 +11,13 @@ struct mb_cache_entry {
unsigned short e_queued;
struct block_device *e_bdev;
sector_t e_block;
- struct list_head e_block_list;
+ struct hlist_bl_node e_block_list;
struct {
- struct list_head o_list;
+ struct hlist_bl_node o_list;
unsigned int o_key;
} e_index;
+ struct hlist_bl_head *e_block_hash_p;
+ struct hlist_bl_head *e_index_hash_p;
};

struct mb_cache {
@@ -25,8 +27,8 @@ struct mb_cache {
int c_max_entries;
int c_bucket_bits;
struct kmem_cache *c_entry_cache;
- struct list_head *c_block_hash;
- struct list_head *c_index_hash;
+ struct hlist_bl_head *c_block_hash;
+ struct hlist_bl_head *c_index_hash;
};

/* Functions on caches */
--
1.7.11.3


\
 
 \ /
  Last update: 2013-08-22 18:21    [W:0.323 / U:2.472 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site