Re: [PACTH v2 0/3] Implement /proc/<pid>/totmaps

From: Michal Hocko
Date: Mon Aug 22 2016 - 13:47:17 EST


On Mon 22-08-16 19:29:36, Michal Hocko wrote:
> On Mon 22-08-16 18:45:54, Michal Hocko wrote:
> [...]
> > I have no idea why those numbers are so different on my laptop
> > yet. It surely looks suspicious. I will try to debug this further
> > tomorrow.
>
> Hmm, so I've tried to use my version of awk on other machine and vice
> versa and it didn't make any difference. So this is independent on the
> awk version it seems. So I've tried to strace /usr/bin/time and
> wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, {ru_utime={0, 0}, ru_stime={0, 688438}, ...}) = 9128
>
> so the kernel indeed reports 0 user time for some reason. Note I
> was testing with 4.7 and right now with 4.8.0-rc3 kernel (no local
> modifications). The other machine which reports non-0 utime is 3.12
> SLES kernel. Maybe I am hitting some accounting bug. At first I was
> suspecting CONFIG_NO_HZ_FULL because that is the main difference between
> my and the other machine but then I've noticed that the tests I was
> doing in kvm have this disabled too.. so it must be something else.

4.5 reports non-0 while 4.6 zero utime. NO_HZ configuration is the same
in both kernels.
--
Michal Hocko
SUSE Labs