lkml.org 
[lkml]   [2008]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: RCU hang on cpu re-hotplug with 2.6.27rc8
[fix up Thomas' address to not bounce]

On Wed, Oct 08, 2008 at 06:33:21PM -0700, Paul E. McKenney wrote:
> The attached patch (similar to one in -tip, but set up for mainline and
> tweaked to make stall-checking on by default) should get you a stack
> trace of any CPUs holding up RCU grace periods for more than about
> three seconds.
>
> On the off-chance that this helps.

It actually does. The stall detector makes the online echo return after three seconds,
although it's not 100% clear to me why.

here's the backtrace

RCU detected CPU 14 stall (t=4295149800/5928 jiffies)
Pid: 0, comm: swapper Not tainted 2.6.27-rc9 #5

Call Trace:
<IRQ> [<ffffffff8025d188>] __rcu_pending+0x6e/0x1d9
[<ffffffff8025d329>] rcu_pending+0x36/0x6e
[<ffffffff8023b480>] update_process_times+0x37/0x5b
[<ffffffff8024be72>] tick_periodic+0x68/0x74
[<ffffffff8024be9f>] tick_handle_periodic+0x21/0x66
[<ffffffff8021bcd2>] smp_apic_timer_interrupt+0x8a/0xa8
[<ffffffff8020bfe6>] apic_timer_interrupt+0x66/0x70
<EOI> [<ffffffff803adb39>] ? acpi_safe_halt+0x2b/0x3e
[<ffffffff803adbfa>] ? acpi_idle_enter_c1+0xae/0x102
[<ffffffff804ffdd6>] ? cpuidle_idle_call+0x70/0xa2
[<ffffffff8020a097>] ? cpu_idle+0x7e/0x9c
[<ffffffff805bef4a>] ? start_secondary+0x157/0x15c

Timer issue?


-Andi


\
 
 \ /
  Last update: 2008-10-09 06:55    [W:0.181 / U:1.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site