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authorVivek Haldar <haldar@google.com>2011-05-22 21:24:16 -0400
committerTheodore Ts'o <tytso@mit.edu>2011-05-22 21:24:16 -0400
commit77f4135f2a219a2127be6cc1208c42e6175b11dd (patch)
tree8f85549d2354c5a69a5b29197f68a554daad1324 /fs/ext4/extents.c
parent93917411be8db5d21abf15c781dfa43c5cc6edf2 (diff)
ext4: count hits/misses of extent cache and expose in sysfs
The number of hits and misses for each filesystem is exposed in /sys/fs/ext4/<dev>/extent_cache_{hits, misses}. Tested: fsstress, manual checks. Signed-off-by: Vivek Haldar <haldar@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/extents.c')
-rw-r--r--fs/ext4/extents.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 9a3844adb1c..4444317d141 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2035,6 +2035,7 @@ ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
struct ext4_extent *ex)
{
struct ext4_ext_cache *cex;
+ struct ext4_sb_info *sbi;
int ret = 0;
/*
@@ -2042,6 +2043,7 @@ ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
*/
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
cex = &EXT4_I(inode)->i_cached_extent;
+ sbi = EXT4_SB(inode->i_sb);
/* has cache valid data? */
if (cex->ec_len == 0)
@@ -2057,6 +2059,10 @@ ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
ret = 1;
}
errout:
+ if (!ret)
+ sbi->extent_cache_misses++;
+ else
+ sbi->extent_cache_hits++;
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return ret;
}
@@ -3901,4 +3907,3 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
return error;
}
-