Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

2016-06-07 15:31 GMT+08:00 Paolo Bonzini : > > > On 07/06/2016 03:24, Rik van Riel wrote: >> On Mon, 2016-06-06 at 15:40 +0200, Paolo Bonzini wrote: >>> >>> On 02/06/2016 15:59, Rik van Riel wrote: If a guest is saved to disk and later restored (eg. after a host

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

2016-06-07 15:31 GMT+08:00 Paolo Bonzini : > > > On 07/06/2016 03:24, Rik van Riel wrote: >> On Mon, 2016-06-06 at 15:40 +0200, Paolo Bonzini wrote: >>> >>> On 02/06/2016 15:59, Rik van Riel wrote: If a guest is saved to disk and later restored (eg. after a host reboot), or live

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On 07/06/2016 03:24, Rik van Riel wrote: > On Mon, 2016-06-06 at 15:40 +0200, Paolo Bonzini wrote: >> >> On 02/06/2016 15:59, Rik van Riel wrote: >>> >>> If a guest is saved to disk and later restored (eg. after >>> a host reboot), or live migrated to another host, I would >>> expect to get

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On 07/06/2016 03:24, Rik van Riel wrote: > On Mon, 2016-06-06 at 15:40 +0200, Paolo Bonzini wrote: >> >> On 02/06/2016 15:59, Rik van Riel wrote: >>> >>> If a guest is saved to disk and later restored (eg. after >>> a host reboot), or live migrated to another host, I would >>> expect to get

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On Mon, 2016-06-06 at 15:40 +0200, Paolo Bonzini wrote: > > On 02/06/2016 15:59, Rik van Riel wrote: > > > > If a guest is saved to disk and later restored (eg. after > > a host reboot), or live migrated to another host, I would > > expect to get totally disjoint steal time statistics from > >

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On Mon, 2016-06-06 at 15:40 +0200, Paolo Bonzini wrote: > > On 02/06/2016 15:59, Rik van Riel wrote: > > > > If a guest is saved to disk and later restored (eg. after > > a host reboot), or live migrated to another host, I would > > expect to get totally disjoint steal time statistics from > >

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

2016-06-06 21:40 GMT+08:00 Paolo Bonzini : > > > On 02/06/2016 15:59, Rik van Riel wrote: >> If a guest is saved to disk and later restored (eg. after >> a host reboot), or live migrated to another host, I would >> expect to get totally disjoint steal time statistics from >>

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

2016-06-06 21:40 GMT+08:00 Paolo Bonzini : > > > On 02/06/2016 15:59, Rik van Riel wrote: >> If a guest is saved to disk and later restored (eg. after >> a host reboot), or live migrated to another host, I would >> expect to get totally disjoint steal time statistics from >> the "new run" of the

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On 02/06/2016 15:59, Rik van Riel wrote: > If a guest is saved to disk and later restored (eg. after > a host reboot), or live migrated to another host, I would > expect to get totally disjoint steal time statistics from > the "new run" of the guest (which is the same run of the > guest OS).

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On 02/06/2016 15:59, Rik van Riel wrote: > If a guest is saved to disk and later restored (eg. after > a host reboot), or live migrated to another host, I would > expect to get totally disjoint steal time statistics from > the "new run" of the guest (which is the same run of the > guest OS).

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

2016-06-02 21:59 GMT+08:00 Rik van Riel : > On Thu, 2016-06-02 at 14:00 +0200, Peter Zijlstra wrote: >> On Thu, Jun 02, 2016 at 07:57:19PM +0800, Wanpeng Li wrote: >> > >> > From: Wanpeng Li >> > >> > I observed that sometimes st is 100% instantaneous,

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

2016-06-02 21:59 GMT+08:00 Rik van Riel : > On Thu, 2016-06-02 at 14:00 +0200, Peter Zijlstra wrote: >> On Thu, Jun 02, 2016 at 07:57:19PM +0800, Wanpeng Li wrote: >> > >> > From: Wanpeng Li >> > >> > I observed that sometimes st is 100% instantaneous, then idle is >> > 100% >> > even if there is

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On Thu, 2016-06-02 at 14:00 +0200, Peter Zijlstra wrote: > On Thu, Jun 02, 2016 at 07:57:19PM +0800, Wanpeng Li wrote: > > > > From: Wanpeng Li > > > > I observed that sometimes st is 100% instantaneous, then idle is > > 100%  > > even if there is a cpu hog on the guest

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On Thu, 2016-06-02 at 14:00 +0200, Peter Zijlstra wrote: > On Thu, Jun 02, 2016 at 07:57:19PM +0800, Wanpeng Li wrote: > > > > From: Wanpeng Li > > > > I observed that sometimes st is 100% instantaneous, then idle is > > 100%  > > even if there is a cpu hog on the guest cpu after the cpu

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On Thu, Jun 02, 2016 at 07:57:19PM +0800, Wanpeng Li wrote: > From: Wanpeng Li > > I observed that sometimes st is 100% instantaneous, then idle is 100% > even if there is a cpu hog on the guest cpu after the cpu hotplug comes > back(N.B. both guest and host are latest

[PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

From: Wanpeng Li I observed that sometimes st is 100% instantaneous, then idle is 100% even if there is a cpu hog on the guest cpu after the cpu hotplug comes back(N.B. both guest and host are latest 4.7-rc1, this can not always be readily reproduced). I add trace to

Re: [PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

On Thu, Jun 02, 2016 at 07:57:19PM +0800, Wanpeng Li wrote: > From: Wanpeng Li > > I observed that sometimes st is 100% instantaneous, then idle is 100% > even if there is a cpu hog on the guest cpu after the cpu hotplug comes > back(N.B. both guest and host are latest 4.7-rc1, this can not

[PATCH] sched/cputime: add steal clock warps handling during cpu hotplug

From: Wanpeng Li I observed that sometimes st is 100% instantaneous, then idle is 100% even if there is a cpu hog on the guest cpu after the cpu hotplug comes back(N.B. both guest and host are latest 4.7-rc1, this can not always be readily reproduced). I add trace to capture it as below: