Messages in this thread | | | Date | Thu, 21 Oct 2010 11:58:56 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH][GIT PULL] tracing: Fix compile issue for trace_sched_wakeup.c |
| |
(2010/10/21 1:43), Jason Baron wrote: > On Wed, Oct 20, 2010 at 05:40:45PM +0200, Ingo Molnar wrote: >> FYI, there's a new mystery hang (sometimes crash) that triggers in -tip - and which >> seems to be tracing related. See the crashlog below - config attached. >> >> It's not bisectable - small changes in the kernel make the bug come/go. (might be a >> race of some sorts) >> >> Thanks, >> >> Ingo >> > > strange b/c it looks like we get though enabling/disabling the > tracepoitns individually, but then when we go to enable all the > tracepoints we hit this hang - perhaps, suggesting a race. Do we always > fail after "Testing all events:" is printed? Does the crash have any > more clues. I will try and re-produce this. > > Also, I noticed some recent changes to text_poke_smp() usage of > stop_machine() on Oct. 14th. That's related to the area where this appears > to hang, so if things were working with this .config before then, that > might be a place to look. Adding Masami to the 'cc list.
Recent changes of text_poke_smp() just removed unnecessary get/put_online_cpu(), so I think it's not related this bug.
It seems there can be a bug in stop_machine() routine under heavy use. usually that is called just once at a time, but jump label and optprobe might call it heavily (thousands times?). So some racy situation can be happen easily.
Thanks,
> > thanks, > > -Jason > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
-- Masami HIRAMATSU 2nd Dept. Linux Technology Center Hitachi, Ltd., Systems Development Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
| |