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authorTheodore Ts'o <tytso@mit.edu>2012-04-16 12:16:20 -0400
committerTheodore Ts'o <tytso@mit.edu>2012-04-16 12:16:20 -0400
commit9cd70b347e9761ea2d2ac3d758c529a48a8193e6 (patch)
treef215d10558a62c34aff4528f1c40f1b154bd6c25 /fs
parent0034102808e0dbbf3a2394b82b1bb40b5778de9e (diff)
downloadlinux-linaro-stable-9cd70b347e9761ea2d2ac3d758c529a48a8193e6.tar.gz
ext4: address scalability issue by removing extent cache statistics
Andi Kleen and Tim Chen have reported that under certain circumstances the extent cache statistics are causing scalability problems due to cache line bounces. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
Diffstat (limited to 'fs')
-rw-r--r--fs/ext4/ext4.h3
-rw-r--r--fs/ext4/extents.c4
-rw-r--r--fs/ext4/super.c16
3 files changed, 0 insertions, 23 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index ab2594a30f86..0e01e90add8b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1203,9 +1203,6 @@ struct ext4_sb_info {
unsigned long s_ext_blocks;
unsigned long s_ext_extents;
#endif
- /* ext4 extent cache stats */
- unsigned long extent_cache_hits;
- unsigned long extent_cache_misses;
/* for buddy allocator */
struct ext4_group_info ***s_group_info;
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1421938e6792..8a12cd207679 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2066,10 +2066,6 @@ static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block,
ret = 1;
}
errout:
- if (!ret)
- sbi->extent_cache_misses++;
- else
- sbi->extent_cache_hits++;
trace_ext4_ext_in_cache(inode, block, ret);
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return ret;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ceebaf853beb..ef7db5044262 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2366,18 +2366,6 @@ static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
EXT4_SB(sb)->s_sectors_written_start) >> 1)));
}
-static ssize_t extent_cache_hits_show(struct ext4_attr *a,
- struct ext4_sb_info *sbi, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_hits);
-}
-
-static ssize_t extent_cache_misses_show(struct ext4_attr *a,
- struct ext4_sb_info *sbi, char *buf)
-{
- return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_misses);
-}
-
static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
struct ext4_sb_info *sbi,
const char *buf, size_t count)
@@ -2435,8 +2423,6 @@ static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
EXT4_RO_ATTR(delayed_allocation_blocks);
EXT4_RO_ATTR(session_write_kbytes);
EXT4_RO_ATTR(lifetime_write_kbytes);
-EXT4_RO_ATTR(extent_cache_hits);
-EXT4_RO_ATTR(extent_cache_misses);
EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
inode_readahead_blks_store, s_inode_readahead_blks);
EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
@@ -2452,8 +2438,6 @@ static struct attribute *ext4_attrs[] = {
ATTR_LIST(delayed_allocation_blocks),
ATTR_LIST(session_write_kbytes),
ATTR_LIST(lifetime_write_kbytes),
- ATTR_LIST(extent_cache_hits),
- ATTR_LIST(extent_cache_misses),
ATTR_LIST(inode_readahead_blks),
ATTR_LIST(inode_goal),
ATTR_LIST(mb_stats),