Messages in this thread | | | Subject | Re: [f2fs-dev] [PATCH v2] f2fs: introduce periodic iostat io latency traces | From | Chao Yu <> | Date | Fri, 13 Aug 2021 09:14:00 +0800 |
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On 2021/8/13 4:52, Jaegeuk Kim wrote: > On 08/11, Chao Yu wrote: >> Hi Daeho, >> >> On 2021/8/4 6:55, Daeho Jeong wrote: >>> From: Daeho Jeong <daehojeong@google.com> >>> >>> 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 F2FS_IOSTAT_IO_LATENCY config option to support printing out >>> IO latency statistics tracepoint events which are minimal things to >>> understand filesystem's I/O related behaviors. 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> >>> >>> --- >>> v2: clean up with wrappers and fix a build breakage reported by >>> kernel test robot <lkp@intel.com> >>> --- >>> fs/f2fs/Kconfig | 9 +++ >> >> I try to apply this patch in my local dev branch, but it failed due to >> conflicting with below commit, it needs to rebase this patch to last dev >> branch. > > I applied this in dev branch. Could you please check?
Yeah, I see.
>>> +config F2FS_IOSTAT_IO_LATENCY >>> + bool "F2FS IO statistics IO latency information" >>> + depends on F2FS_FS >>> + default n >>> + help >>> + Support printing out periodic IO latency statistics tracepoint >>> + events. With this, you have to turn on "iostat_enable" sysfs >>> + node to print this out. >> >> This functionality looks independent, how about introuducing iostat.h >> and iostat.c (not sure, maybe trace.[hc])to include newly added structure >> and functions for dispersive codes cleanup.
Thoughts? this also can avoid using CONFIG_F2FS_IOSTAT_IO_LATENCY in many places.
Thanks,
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