Messages in this thread | | | Date | Tue, 1 Sep 2015 10:56:27 +0200 | From | Ingo Molnar <> | Subject | Re: [GIT PULL] scheduler changes for v4.3 |
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* Markus Trippelsdorf <markus@trippelsdorf.de> wrote:
> On 2015.09.01 at 10:38 +0200, Ingo Molnar wrote: > > > > * Markus Trippelsdorf <markus@trippelsdorf.de> wrote: > > > > > Well, git show a1d8561172f369ba56d636df49a6b4d6d77e2123 : > > > > > > commit a1d8561172f369ba56d636df49a6b4d6d77e2123 > > > Merge: 3959df1dfb95 ff277d4250fe > > > Author: Linus Torvalds <torvalds@linux-foundation.org> > > > Date: Mon Aug 31 20:26:22 2015 -0700 > > > > > diff --cc kernel/cpu.c > > > index 3c91a3fdfce5,664ce5299334..82cf9dff4295 > > > --- a/kernel/cpu.c > > > +++ b/kernel/cpu.c > > > @@@ -394,15 -392,10 +394,15 @@@ static int _cpu_down(unsigned int cpu, > > > smpboot_park_threads(cpu); > > > > > > /* > > > - * So now all preempt/rcu users must observe !cpu_active(). > > > + * Prevent irq alloc/free while the dying cpu reorganizes the > > > + * interrupt affinities. > > > */ > > > + irq_lock_sparse(); > > > > > > + /* > > > + * So now all preempt/rcu users must observe !cpu_active(). > > > + */ > > > - err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); > > > + err = stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); > > > if (err) { > > > /* CPU didn't die: tell everyone. Can't complain. */ > > > cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); > > > > So the irq_lock_sparse() change is from a commit that got merged in the last merge > > window, which is part of v4.2: > > > > ce0d3c0a6fb1 ("genirq: Revert sparse irq locking around __cpu_up() and move it to x86 for now") > > > > Could you please post the patch against Linus's latest that you have tested on > > your system to make it boot fine? > > > > The one you posted cannot possibly build, because access to __stop_machine() is > > gone from cpu.c: > > As I wrote in my other reply. The boot failure is nondeterministic (boot > succeeds roughly every sixth time). So the bisection and the patch is > just bogus (,but the boot failure is real). > > Sorry.
No problem. Please let us know if any of these commits does turn out to be the culprit. (Which is always a possibility.)
Thanks,
Ingo
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