Messages in this thread | | | Date | Thu, 24 Jul 2014 10:43:35 +0900 | From | Michel Dänzer <> | Subject | Re: Random panic in load_balance() with 3.16-rc |
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On 24.07.2014 04:20, Linus Torvalds wrote: > On Wed, Jul 23, 2014 at 12:02 PM, Peter Zijlstra <peterz@infradead.org> wrote: >> >> Here goes.. > > Oh. So this doesn't have CPUMASK_OFFSTACK set at all, so the pointer > has never been loaded from memory in the first place. The calculation > has been (for me) something like > > movq $load_balance_mask, %rax > add %gs:this_cpu_off, %rax > > and then gcc is being stupid and saving it to the frame and reloading > it for no good reason (at least for me it *also* saved the value in > %rbx in order to save it into "env.cpus", and the stack spill seems to > be just moronic). > > In Michel's oops, %rbx doesn't contain the pointer any more, though, > so he clearly does have a different compiler. His frame offsets are > rather different too ("-136(%rbp)" vs "-168(%rbp)") so looking at > whether possibly some stack frame got overwritten is clearly very > compiler-specific. > > Michel, mind doing > > make kernel/sched/fair.s > > and sending us the resulting file?
Here it is, gzipped, hope that's okay.
Note that my tree is now based on 3.16-rc6.
-- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer [unhandled content-type:application/gzip] | |