Messages in this thread | | | Date | Tue, 24 Nov 2015 11:09:56 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 3/4] sched: introduce synchronized idle injection |
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On Tue, Nov 24, 2015 at 09:12:40AM +0000, Javi Merino wrote: > On Mon, Nov 23, 2015 at 07:07:06PM +0100, Peter Zijlstra wrote: > > On Mon, Nov 23, 2015 at 05:56:44PM +0000, Javi Merino wrote: > > > I've tested this series on Juno (2xCortex-A57 4xCortex-A53). If you > > > idle inject for 50% of the time, when I run 6 busy loops the scheduler > > > sometimes keeps two of them in the same cpu while the another cpu is > > > completely idle. Without idle injection the scheduler does the > > > sensible thing: put one busy loop in each CPU. I'm running systemd > > > and this only happens with CONFIG_SCHED_AUTOGROUP=y. If I unset > > > CONFIG_SCHED_AUTOGROUP, the tasks are spread across all cpus as usual. > > > > That's not a plus for this patch though; but a bug report against > > AUTOGROUP/cgroup muck, right? > > The bug only happens when you apply this series and you set the system > to idle inject 50% of the time. SCHED_AUTOGROUP is already part of > the kernel and behaves properly with the kernel as is. I think that > this patch should not introduce new bugs.
Ah, then I misunderstood your email, agreed.
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