Messages in this thread |  | | | Date | Sat, 26 Mar 2011 19:49:34 +0100 | | From | Oleg Nesterov <> | | Subject | Re: [PATCH,RFC] perf: panic due to inclied cpu context task_ctx value |
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On 03/26, Peter Zijlstra wrote: > > On Sat, 2011-03-26 at 18:35 +0100, Oleg Nesterov wrote: > > > > but probably we also need update_context_time(). > > It looks like event_sched_out() relies on up-to-date ctx->time through > perf_event_time() and most call-paths leading to event_sched_out() do > indeed seem to update the ctx time, all except the move_group branch in > perf_event_open() afaict.
OK, thanks...
> Sadly the reproducer doesn't seem to trigger the issue at all, its still > running on a plain -tip kernel.
This test-case is not "perfect", the task should change its CPU after it closes the last perf_even_fd and before it exits...
But to me, the main question is: I do not understand how this test-case can ever trigger the problem with HAVE_JUMP_LABEL. But it does.
I didn't try to reproduce, my gcc is old and not-CC_HAVE_ASM_GOTO.
Oleg.
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