Re: [PATCH] time,virt: resync steal time when guest & host lose sync

From	Wanpeng Li <kernellwp@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] time,virt: resync steal time when guest & host lose sync
Date	2016-08-16 00:20 +0200
Message-ID	<s6yoG-35D-27@gated-at.bofh.it> (permalink)
References	(8 earlier) <s5aHL-4bR-21@gated-at.bofh.it> <s5eLo-6Xs-7@gated-at.bofh.it> <s5n2h-3z3-1@gated-at.bofh.it> <s6lUu-3kK-27@gated-at.bofh.it> <s6rGy-7aD-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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2016-08-15 23:00 GMT+08:00 Rik van Riel <riel@redhat.com>:
> On Mon, 2016-08-15 at 16:53 +0800, Wanpeng Li wrote:
>> 2016-08-12 23:58 GMT+08:00 Rik van Riel <riel@redhat.com>:
>> [...]
>> > Wanpeng, does the patch below work for you?
>>
>> It will break steal time for full dynticks guest, and there is a
>> calltrace of thread_group_cputime_adjusted call stack, RIP is
>> cputime_adjust+0xff/0x130.
>
> How?  This patch is equivalent to passing ULONG_MAX to
> steal_account_process_time, which you tried to no ill
> effect before.

https://lkml.org/lkml/2016/8/15/217 I sent out a patch yesterday which
can fix the regression. Your patch breaks full dynticks guest since
vtime doesn't depend on clock ticks, so we should keep the max cputime
limit for it as my patch description mentioned, remove the limit for
vtime results in the calltrace. My patch does what Paolo suggested
https://lkml.org/lkml/2016/8/12/380 for lost ticks scenario.

Regards,
Wanpeng Li

Thread

Re: [PATCH] time,virt: resync steal time when guest & host lose sync Wanpeng Li <kernellwp@gmail.com> - 2016-08-11 12:20 +0200
  Re: [PATCH] time,virt: resync steal time when guest & host lose sync Rik van Riel <riel@redhat.com> - 2016-08-12 04:50 +0200
    Re: [PATCH] time,virt: resync steal time when guest & host lose sync Wanpeng Li <kernellwp@gmail.com> - 2016-08-12 09:10 +0200
      Re: [PATCH] time,virt: resync steal time when guest & host lose  sync Rik van Riel <riel@redhat.com> - 2016-08-12 18:00 +0200
        Re: [PATCH] time,virt: resync steal time when guest & host lose sync Frederic Weisbecker <fweisbec@gmail.com> - 2016-08-13 17:40 +0200
        Re: [PATCH] time,virt: resync steal time when guest & host lose sync Wanpeng Li <kernellwp@gmail.com> - 2016-08-15 11:00 +0200
          Re: [PATCH] time,virt: resync steal time when guest & host lose sync Wanpeng Li <kernellwp@gmail.com> - 2016-08-15 13:40 +0200
          Re: [PATCH] time,virt: resync steal time when guest & host lose sync Rik van Riel <riel@redhat.com> - 2016-08-15 17:10 +0200
            Re: [PATCH] time,virt: resync steal time when guest & host lose sync Wanpeng Li <kernellwp@gmail.com> - 2016-08-16 00:20 +0200
            Re: [PATCH] time,virt: resync steal time when guest & host lose sync Wanpeng Li <kernellwp@gmail.com> - 2016-08-16 03:40 +0200
              Re: [PATCH] time,virt: resync steal time when guest & host lose sync Rik van Riel <riel@redhat.com> - 2016-08-16 04:20 +0200
                Re: [PATCH] time,virt: resync steal time when guest & host lose sync Wanpeng Li <kernellwp@gmail.com> - 2016-08-16 09:00 +0200
                Re: [PATCH] time,virt: resync steal time when guest & host lose sync Rik van Riel <riel@redhat.com> - 2016-08-16 16:20 +0200
                Re: [PATCH] time,virt: resync steal time when guest & host lose sync Wanpeng Li <kernellwp@gmail.com> - 2016-08-17 01:10 +0200

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