Messages in this thread | | | From | Amir Goldstein <> | Date | Sun, 26 Jul 2020 14:52:47 +0300 | Subject | Re: [fsnotify] c738fbabb0: will-it-scale.per_process_ops -9.5% regression |
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On Fri, Jul 24, 2020 at 6:47 AM Amir Goldstein <amir73il@gmail.com> wrote: > > On Fri, Jul 24, 2020 at 5:45 AM Rong Chen <rong.a.chen@intel.com> wrote: > > > > > > > > On 7/21/20 11:59 PM, Amir Goldstein wrote: > > > On Tue, Jul 21, 2020 at 3:15 AM kernel test robot <rong.a.chen@intel.com> wrote: > > >> Greeting, > > >> > > >> FYI, we noticed a -9.5% regression of will-it-scale.per_process_ops due to commit: > > >> > > >> > > >> commit: c738fbabb0ff62d0f9a9572e56e65d05a1b34c6a ("fsnotify: fold fsnotify() call into fsnotify_parent()") > > > Strange, that's a pretty dumb patch moving some inlined code from one > > > function to > > > another (assuming there are no fsnotify marks in this test). > > > > > > Unless I am missing something the only thing that changes slightly is > > > an extra d_inode(file->f_path.dentry) deference. > > > I can get rid of it. > > > > > > Is it possible to ask for a re-test with fix patch (attached)? > > > > Hi Amir, > > > > We failed to apply this patch, could you tell us the base commit or the > > base branch? > > > > Hi Rong, > > The patch is applied on top of the reported offending commit: > c738fbabb0ff62d0f9a9572e56e65d05a1b34c6a ("fsnotify: fold fsnotify() > call into fsnotify_parent()") > > I pushed it to my github: > https://github.com/amir73il/linux/commits/for_lkp >
FWIW, I tried reproducing the reported regression on a local machine.
I ran the test twice on each of the branch commits:
26dc3d2bff62 fsnotify: pass inode to fsnotify_parent() c738fbabb0ff fsnotify: fold fsnotify() call into fsnotify_parent() 71d734103edf fsnotify: Rearrange fast path to minimise overhead when there is no watcher 47aaabdedf36 fanotify: Avoid softlockups when reading many events
Not only did I not observe a regression with the reported commit, but there was a slight improvement. And then there yet was another improvement with the fix commit on top of it.
But it could be that I am doing something wrong, because I have zero millage with LKP.
========================================================================================= compiler/cpufreq_governor/kconfig/mode/nr_task/rootfs/tbox_group/test/testcase: gcc-7/performance/defconfig/process/16/ubuntu/amir-lkp/open1/will-it-scale
commit: 47aaabdedf366ac5894c7fddec388832f0d8193e 71d734103edfa2b4c6657578a3082ee0e51d767e c738fbabb0ff62d0f9a9572e56e65d05a1b34c6a 26dc3d2bff623768cbbd0c8053ddd6390fd828d2
47aaabdedf366ac5 71d734103edfa2b4c6657578a30 c738fbabb0ff62d0f9a9572e56e 26dc3d2bff623768cbbd0c8053d ---------------- --------------------------- --------------------------- --------------------------- fail:runs %reproduction fail:runs %reproduction fail:runs %reproduction fail:runs | | | | | | | 45:2 -555% 34:2 -807% 29:2 -996% 25:2 dmesg.timestamp:last 45:2 -555% 34:2 -807% 29:2 -996% 25:2 kmsg.timestamp:last %stddev %change %stddev %change %stddev %change %stddev \ | \ | \ | \ 1097404 +1.7% 1116452 +2.7% 1126533 +3.5% 1135663 will-it-scale.16.processes 0.02 ± 60% +20.0% 0.03 ± 66% +20.0% 0.03 ± 66% -20.0% 0.02 ± 50% will-it-scale.16.processes_idle 68587 +1.7% 69778 +2.7% 70408 +3.5% 70978 will-it-scale.per_process_ops
Thanks, Amir.
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