dd02d4234c
cpuacct has 2 different ways of accounting and showing user
and system times.
The first one uses cpuacct_account_field() to account times
and cpuacct.stat file to expose them. And this one seems to work ok.
The second one is uses cpuacct_charge() function for accounting and
set of cpuacct.usage* files to show times. Despite some attempts to
fix it in the past it still doesn't work. Sometimes while running KVM
guest the cpuacct_charge() accounts most of the guest time as
system time. This doesn't match with user&system times shown in
cpuacct.stat or proc/<pid>/stat.
Demonstration:
# git clone https://github.com/aryabinin/kvmsample
# make
# mkdir /sys/fs/cgroup/cpuacct/test
# echo $$ > /sys/fs/cgroup/cpuacct/test/tasks
# ./kvmsample &
# for i in {1..5}; do cat /sys/fs/cgroup/cpuacct/test/cpuacct.usage_sys; sleep 1; done
1976535645
2979839428
3979832704
4983603153
5983604157
Use cpustats accounted in cpuacct_account_field() as the source
of user/sys times for cpuacct.usage* files. Make cpuacct_charge()
to account only summary execution time.
Fixes:
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.. | ||
autogroup.c | ||
autogroup.h | ||
clock.c | ||
completion.c | ||
core_sched.c | ||
core.c | ||
cpuacct.c | ||
cpudeadline.c | ||
cpudeadline.h | ||
cpufreq_schedutil.c | ||
cpufreq.c | ||
cpupri.c | ||
cpupri.h | ||
cputime.c | ||
deadline.c | ||
debug.c | ||
fair.c | ||
features.h | ||
idle.c | ||
isolation.c | ||
loadavg.c | ||
Makefile | ||
membarrier.c | ||
pelt.c | ||
pelt.h | ||
psi.c | ||
rt.c | ||
sched-pelt.h | ||
sched.h | ||
smp.h | ||
stats.c | ||
stats.h | ||
stop_task.c | ||
swait.c | ||
topology.c | ||
wait_bit.c | ||
wait.c |