Re: [tip:core/rcu] rcu: Fix holdoff for accelerated GPs for lastnon-dynticked CPU

From: Ingo Molnar
Date: Wed Mar 17 2010 - 13:53:24 EST



* Ingo Molnar <mingo@xxxxxxx> wrote:

> incidentally i have a RCU badness crash log from another box:
>
> [ 4.573332] initcall ipmi_init_msghandler_mod+0x0/0xd returned 0 after 0 usecs
> [ 4.573332] calling init_ipmi_si+0x0/0x435 @ 1
> [ 4.573332] IPMI System Interface driver.
> [ 4.573340] [<ffffffff81022cdc>] no_context+0x1fc/0x20b
> [ 4.576672] [<ffffffff81002a16>] ? ftrace_call+0x5/0x2b
> [ 4.580021] [<ffffffff81022e77>] __bad_area_nosemaphore+0x18c/0x1af
> [ 4.583338] [<ffffffff81002a16>] ? ftrace_call+0x5/0x2b
> [ 4.586672] [<ffffffff81022ead>] bad_area_nosemaphore+0x13/0x15
> [ 4.590005] [<ffffffff81023159>] do_page_fault+0x138/0x284
> [ 4.593354] [<ffffffff81a632bf>] page_fault+0x1f/0x30

I spent a few hours yesterday and today trying to track this down, but failed
to bisect it. The crash is sporadic on many configs - which confused my
bisection attempts. Sometimes it crashes only after 10 reboots. Was able to
crash v2.6.30 as well, so it's an older bug. v2.6.29 was not testable on that
box due to network driver problems so i stopped there.

Ingo
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