* nice value is ignored on cpu time accounting of a guest? @ 2009-10-19 9:46 Ryota Ozaki 2009-10-20 5:21 ` Avi Kivity 0 siblings, 1 reply; 7+ messages in thread From: Ryota Ozaki @ 2009-10-19 9:46 UTC (permalink / raw) To: kvm; +Cc: Ryota OZAKI Hi, I have a question on cputime accounting of a guest. CPU time of a guest is always accounted as 'user' time of cpustat even if nice value of the guest is higher than 0. Is there a reason to do so? I think the cpu time of the guest should be accounted into 'nice' as same as a normal process. Am I wrong? ozaki-r ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: nice value is ignored on cpu time accounting of a guest? 2009-10-19 9:46 nice value is ignored on cpu time accounting of a guest? Ryota Ozaki @ 2009-10-20 5:21 ` Avi Kivity 2009-10-20 7:06 ` Ryota Ozaki 0 siblings, 1 reply; 7+ messages in thread From: Avi Kivity @ 2009-10-20 5:21 UTC (permalink / raw) To: Ryota Ozaki; +Cc: kvm On 10/19/2009 06:46 PM, Ryota Ozaki wrote: > Hi, > > I have a question on cputime accounting of a guest. CPU time of a > guest is always > accounted as 'user' time of cpustat even if nice value of the guest is > higher than 0. > Is there a reason to do so? I think the cpu time of the guest should > be accounted > into 'nice' as same as a normal process. Am I wrong? > Hm, guest time is accounted separately, and added to user time in /proc (so tools that don't know about guest time can read it as user time). Looks like we need to add a separate guest_nice, or get rid of guest time altogether. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: nice value is ignored on cpu time accounting of a guest? 2009-10-20 5:21 ` Avi Kivity @ 2009-10-20 7:06 ` Ryota Ozaki 2009-10-20 7:17 ` Avi Kivity 0 siblings, 1 reply; 7+ messages in thread From: Ryota Ozaki @ 2009-10-20 7:06 UTC (permalink / raw) To: Avi Kivity; +Cc: kvm, Ryota OZAKI On Tue, Oct 20, 2009 at 2:21 PM, Avi Kivity <avi@redhat.com> wrote: > On 10/19/2009 06:46 PM, Ryota Ozaki wrote: >> >> Hi, >> >> I have a question on cputime accounting of a guest. CPU time of a >> guest is always >> accounted as 'user' time of cpustat even if nice value of the guest is >> higher than 0. >> Is there a reason to do so? I think the cpu time of the guest should >> be accounted >> into 'nice' as same as a normal process. Am I wrong? >> > > Hm, guest time is accounted separately, and added to user time in /proc (so > tools that don't know about guest time can read it as user time). Yes, but I think always added to user time without regard to nice value is a problem. I want to fix it because user time is an account for processes that have nice == 0. > > Looks like we need to add a separate guest_nice, or get rid of guest time > altogether. Hmm, guest time is already exposed via /proc/stat so adding guest_nice is better if fix here? I don't know anyone utilize 'guest' value though. ozaki-r > > -- > I have a truly marvellous patch that fixes the bug which this > signature is too narrow to contain. > > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: nice value is ignored on cpu time accounting of a guest? 2009-10-20 7:06 ` Ryota Ozaki @ 2009-10-20 7:17 ` Avi Kivity 2009-10-20 7:27 ` Ryota Ozaki 0 siblings, 1 reply; 7+ messages in thread From: Avi Kivity @ 2009-10-20 7:17 UTC (permalink / raw) To: Ryota Ozaki; +Cc: kvm On 10/20/2009 04:06 PM, Ryota Ozaki wrote: >> Looks like we need to add a separate guest_nice, or get rid of guest time >> altogether. >> > Hmm, guest time is already exposed via /proc/stat so adding guest_nice is better > if fix here? I don't know anyone utilize 'guest' value though. > No one uses guest time to my knowledge. However, we can't be sure, so it's better to add guest_nice. Note you need to add guest_nice to user_nice, so old tools see it as nice time (same as guest_time now). -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: nice value is ignored on cpu time accounting of a guest? 2009-10-20 7:17 ` Avi Kivity @ 2009-10-20 7:27 ` Ryota Ozaki 2009-10-20 7:34 ` Avi Kivity 0 siblings, 1 reply; 7+ messages in thread From: Ryota Ozaki @ 2009-10-20 7:27 UTC (permalink / raw) To: Avi Kivity; +Cc: kvm, Ryota OZAKI On Tue, Oct 20, 2009 at 4:17 PM, Avi Kivity <avi@redhat.com> wrote: > On 10/20/2009 04:06 PM, Ryota Ozaki wrote: >>> >>> Looks like we need to add a separate guest_nice, or get rid of guest time >>> altogether. >>> >> >> Hmm, guest time is already exposed via /proc/stat so adding guest_nice is >> better >> if fix here? I don't know anyone utilize 'guest' value though. >> > > No one uses guest time to my knowledge. However, we can't be sure, so it's > better to add guest_nice. > > Note you need to add guest_nice to user_nice, so old tools see it as nice > time (same as guest_time now). Well, like this? /* Add user time to cpustat. */ tmp = cputime_to_cputime64(cputime); if (TASK_NICE(p) > 0) { cpustat->nice = cputime64_add(cpustat->nice, tmp); cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); } else { cpustat->user = cputime64_add(cpustat->user, tmp); cpustat->guest = cputime64_add(cpustat->guest, tmp); } ozaki-r ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: nice value is ignored on cpu time accounting of a guest? 2009-10-20 7:27 ` Ryota Ozaki @ 2009-10-20 7:34 ` Avi Kivity 2009-10-20 7:38 ` Ryota Ozaki 0 siblings, 1 reply; 7+ messages in thread From: Avi Kivity @ 2009-10-20 7:34 UTC (permalink / raw) To: Ryota Ozaki; +Cc: kvm On 10/20/2009 04:27 PM, Ryota Ozaki wrote: > On Tue, Oct 20, 2009 at 4:17 PM, Avi Kivity<avi@redhat.com> wrote: > >> On 10/20/2009 04:06 PM, Ryota Ozaki wrote: >> >>>> Looks like we need to add a separate guest_nice, or get rid of guest time >>>> altogether. >>>> >>>> >>> Hmm, guest time is already exposed via /proc/stat so adding guest_nice is >>> better >>> if fix here? I don't know anyone utilize 'guest' value though. >>> >>> >> No one uses guest time to my knowledge. However, we can't be sure, so it's >> better to add guest_nice. >> >> Note you need to add guest_nice to user_nice, so old tools see it as nice >> time (same as guest_time now). >> > Well, like this? > > /* Add user time to cpustat. */ > tmp = cputime_to_cputime64(cputime); > if (TASK_NICE(p)> 0) { > cpustat->nice = cputime64_add(cpustat->nice, tmp); > cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); > } else { > cpustat->user = cputime64_add(cpustat->user, tmp); > cpustat->guest = cputime64_add(cpustat->guest, tmp); > } > In account_guest_time()? Yes. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: nice value is ignored on cpu time accounting of a guest? 2009-10-20 7:34 ` Avi Kivity @ 2009-10-20 7:38 ` Ryota Ozaki 0 siblings, 0 replies; 7+ messages in thread From: Ryota Ozaki @ 2009-10-20 7:38 UTC (permalink / raw) To: Avi Kivity; +Cc: kvm, Ryota OZAKI On Tue, Oct 20, 2009 at 4:34 PM, Avi Kivity <avi@redhat.com> wrote: > On 10/20/2009 04:27 PM, Ryota Ozaki wrote: >> Well, like this? >> >> /* Add user time to cpustat. */ >> tmp = cputime_to_cputime64(cputime); >> if (TASK_NICE(p)> 0) { >> cpustat->nice = cputime64_add(cpustat->nice, tmp); >> cpustat->guest_nice = cputime64_add(cpustat->guest_nice, >> tmp); >> } else { >> cpustat->user = cputime64_add(cpustat->user, tmp); >> cpustat->guest = cputime64_add(cpustat->guest, tmp); >> } >> > > In account_guest_time()? Yes. Yes. OK, I'll send a patch later. Thanks! ozaki-r ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2009-10-20 7:38 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2009-10-19 9:46 nice value is ignored on cpu time accounting of a guest? Ryota Ozaki 2009-10-20 5:21 ` Avi Kivity 2009-10-20 7:06 ` Ryota Ozaki 2009-10-20 7:17 ` Avi Kivity 2009-10-20 7:27 ` Ryota Ozaki 2009-10-20 7:34 ` Avi Kivity 2009-10-20 7:38 ` Ryota Ozaki
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