Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit d7fbd893388d9e86d29b7cfbd5457bcf03496fbf

Authored by Ajeet Yadav
Committed by Phillip Lougher
1 parent 89cab5b572
Exists in master and in 6 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

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>

Showing 2 changed files with 9 additions and 3 deletions Side-by-side Diff

... ... @@ -70,11 +70,15 @@
70 70 spin_lock(&cache->lock);
71 71  
72 72 while (1) {
73   - for (i = 0; i < cache->entries; i++)
74   - if (cache->entry[i].block == block)
  73 + for (i = cache->curr_blk, n = 0; n < cache->entries; n++) {
  74 + if (cache->entry[i].block == block) {
  75 + cache->curr_blk = i;
75 76 break;
  77 + }
  78 + i = (i + 1) % cache->entries;
  79 + }
76 80  
77   - if (i == cache->entries) {
  81 + if (n == cache->entries) {
78 82 /*
79 83 * Block not in cache, if all cache entries are used
80 84 * go to sleep waiting for one to become available.
... ... @@ -245,6 +249,7 @@
245 249 goto cleanup;
246 250 }
247 251  
  252 + cache->curr_blk = 0;
248 253 cache->next_blk = 0;
249 254 cache->unused = entries;
250 255 cache->entries = entries;
fs/squashfs/squashfs_fs_sb.h
Diff comments   View file @ d7fbd89
... ... @@ -28,6 +28,7 @@
28 28 struct squashfs_cache {
29 29 char *name;
30 30 int entries;
  31 + int curr_blk;
31 32 int next_blk;
32 33 int num_waiters;
33 34 int unused;