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| author | Ajeet Yadav <ajeet.yadav.77@gmail.com> | 2011-12-27 15:10:04 +0530 |
|---|---|---|
| committer | Phillip Lougher <phillip@squashfs.org.uk> | 2011-12-30 01:24:13 +0000 |
| commit | d7fbd893388d9e86d29b7cfbd5457bcf03496fbf (patch) | |
| tree | ea94d043ee3e842f7273391b143a5949afb39975 /fs/squashfs | |
| parent | 89cab5b5727d3139adc247e3a3d4ee5b10e3eda5 (diff) | |
| download | lwn-d7fbd893388d9e86d29b7cfbd5457bcf03496fbf.tar.gz lwn-d7fbd893388d9e86d29b7cfbd5457bcf03496fbf.zip | |
Squashfs: optimise squashfs_cache_get entry search
squashfs_cache_get() iterates over all entries to search for
block its looking for. Often get() / put() are called for
same block.
If we cache the current entry index, then we can optimise the
subsequent *_get() calls.
Signed-off-by: Ajeet Yadav <ajeet.yadav.77@gmail.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Diffstat (limited to 'fs/squashfs')
| -rw-r--r-- | fs/squashfs/cache.c | 11 | ||||
| -rw-r--r-- | fs/squashfs/squashfs_fs_sb.h | 1 |
2 files changed, 9 insertions, 3 deletions
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c index ea6e798e548b..af0b73802592 100644 --- a/fs/squashfs/cache.c +++ b/fs/squashfs/cache.c @@ -70,11 +70,15 @@ struct squashfs_cache_entry *squashfs_cache_get(struct super_block *sb, spin_lock(&cache->lock); while (1) { - for (i = 0; i < cache->entries; i++) - if (cache->entry[i].block == block) + for (i = cache->curr_blk, n = 0; n < cache->entries; n++) { + if (cache->entry[i].block == block) { + cache->curr_blk = i; break; + } + i = (i + 1) % cache->entries; + } - if (i == cache->entries) { + if (n == cache->entries) { /* * Block not in cache, if all cache entries are used * go to sleep waiting for one to become available. @@ -245,6 +249,7 @@ struct squashfs_cache *squashfs_cache_init(char *name, int entries, goto cleanup; } + cache->curr_blk = 0; cache->next_blk = 0; cache->unused = entries; cache->entries = entries; diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h index 651f0b31d296..52934a22f296 100644 --- a/fs/squashfs/squashfs_fs_sb.h +++ b/fs/squashfs/squashfs_fs_sb.h @@ -28,6 +28,7 @@ struct squashfs_cache { char *name; int entries; + int curr_blk; int next_blk; int num_waiters; int unused; |