linux/fs/f2fs
Daeho Jeong a4b6817625 f2fs: introduce periodic iostat io latency traces
Whenever we notice some sluggish issues on our machines, we are always
curious about how well all types of I/O in the f2fs filesystem are
handled. But, it's hard to get this kind of real data. First of all,
we need to reproduce the issue while turning on the profiling tool like
blktrace, but the issue doesn't happen again easily. Second, with the
intervention of any tools, the overall timing of the issue will be
slightly changed and it sometimes makes us hard to figure it out.

So, I added the feature printing out IO latency statistics tracepoint
events, which are minimal things to understand filesystem's I/O related
behaviors, into F2FS_IOSTAT kernel config. With "iostat_enable" sysfs
node on, we can get this statistics info in a periodic way and it
would cause the least overhead.

[samples]
 f2fs_ckpt-254:1-507     [003] ....  2842.439683: f2fs_iostat_latency:
dev = (254,11), iotype [peak lat.(ms)/avg lat.(ms)/count],
rd_data [136/1/801], rd_node [136/1/1704], rd_meta [4/2/4],
wr_sync_data [164/16/3331], wr_sync_node [152/3/648],
wr_sync_meta [160/2/4243], wr_async_data [24/13/15],
wr_async_node [0/0/0], wr_async_meta [0/0/0]

 f2fs_ckpt-254:1-507     [002] ....  2845.450514: f2fs_iostat_latency:
dev = (254,11), iotype [peak lat.(ms)/avg lat.(ms)/count],
rd_data [60/3/456], rd_node [60/3/1258], rd_meta [0/0/1],
wr_sync_data [120/12/2285], wr_sync_node [88/5/428],
wr_sync_meta [52/6/2990], wr_async_data [4/1/3],
wr_async_node [0/0/0], wr_async_meta [0/0/0]

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-08-23 10:25:51 -07:00
..
acl.c f2fs: clean up build warnings 2021-04-10 10:36:39 -07:00
acl.h fs: make helpers idmap mount aware 2021-01-24 14:27:20 +01:00
checkpoint.c f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
compress.c f2fs: compress: do sanity check on cluster 2021-08-17 11:59:06 -07:00
data.c f2fs: introduce periodic iostat io latency traces 2021-08-23 10:25:51 -07:00
debug.c f2fs: convert S_IRUGO to 0444 2021-08-17 11:59:05 -07:00
dir.c f2fs: support fault injection for f2fs_kmem_cache_alloc() 2021-08-17 11:59:05 -07:00
extent_cache.c f2fs: support fault injection for f2fs_kmem_cache_alloc() 2021-08-17 11:59:05 -07:00
f2fs.h f2fs: introduce periodic iostat io latency traces 2021-08-23 10:25:51 -07:00
file.c f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
gc.c f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
gc.h f2fs: introduce gc_merge mount option 2021-03-30 18:48:56 -07:00
hash.c f2fs: Handle casefolding with Encryption 2020-12-02 22:00:21 -08:00
inline.c f2fs: restructure f2fs page.private layout 2021-05-14 11:22:08 -07:00
inode.c f2fs: compress: add compress_inode to cache compressed blocks 2021-06-23 01:09:35 -07:00
iostat.c f2fs: introduce periodic iostat io latency traces 2021-08-23 10:25:51 -07:00
iostat.h f2fs: introduce periodic iostat io latency traces 2021-08-23 10:25:51 -07:00
Kconfig f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
Makefile f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
namei.c f2fs: compress: add nocompress extensions support 2021-07-01 18:34:31 -07:00
node.c f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
node.h f2fs: swap: support migrating swapfile in aligned write mode 2021-06-23 01:09:35 -07:00
recovery.c f2fs: support fault injection for f2fs_kmem_cache_alloc() 2021-08-17 11:59:05 -07:00
segment.c f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
segment.h f2fs: correct comment in segment.h 2021-08-13 11:57:08 -07:00
shrinker.c f2fs: avoid race condition for shrinker count 2020-12-03 00:59:26 -08:00
super.c f2fs: introduce periodic iostat io latency traces 2021-08-23 10:25:51 -07:00
sysfs.c f2fs: separate out iostat feature 2021-08-23 10:25:51 -07:00
verity.c f2fs-for-5.13-rc1 2021-05-04 18:03:38 -07:00
xattr.c f2fs: support fault injection for f2fs_kmem_cache_alloc() 2021-08-17 11:59:05 -07:00
xattr.h f2fs: code cleanup by removing ifdef macro surrounding 2020-05-26 18:56:10 -07:00