Messages in this thread Patch in this message | | | Date | Tue, 22 Jul 2014 11:47:40 +0200 | From | Peter Zijlstra <> | Subject | Re: Scheduler regression from caffcdd8d27ba78730d5540396ce72ad022aff2c |
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On Mon, Jul 21, 2014 at 06:52:12PM +0200, Peter Zijlstra wrote: > On Mon, Jul 21, 2014 at 11:35:28AM -0500, Bruno Wolff III wrote: > > Is there more I can do to help with this now? Or should I just wait for > > patches to test? > > Yeah, sorry, was wiped out today. I'll go stare harder at the P4 > topology setup code tomorrow. Something fishy there.
Does this make your machine boot again (while giving an error)?
It tries to robustify the topology setup a bit, crashing on crap input should be avoided if possible of course.
I'll go stare at the x86/P4 topology code like promised.
--- Subject: sched: Robustify topology setup From: Peter Zijlstra <peterz@infradead.org> Date: Mon Jul 21 23:07:06 CEST 2014
We hard assume that higher topology levels are strict supersets of lower levels.
Detect, warn and try to fixup when we encounter this violated.
Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-cgp9j2tk0qnunhtpps3udsom@git.kernel.org --- kernel/sched/core.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
--- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6480,6 +6480,20 @@ struct sched_domain *build_sched_domain( sched_domain_level_max = max(sched_domain_level_max, sd->level); child->parent = sd; sd->child = child; + + if (!cpumask_subset(sched_domain_span(child), + sched_domain_span(sd))) { + pr_err("BUG: arch topology borken\n"); +#ifdef CONFIG_SCHED_DEBUG + pr_err(" the %s domain not a subset of the %s domain\n", + child->name, sd->name); +#endif + /* Fixup, ensure @sd has at least @child cpus. */ + cpumask_or(sched_domain_span(sd), + sched_domain_span(sd), + sched_domain_span(child)); + } + } set_domain_attribute(sd, attr);
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