lkml.org 
[lkml]   [2015]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: qemu:arm test failure due to commit 8053871d0f7f (smp: Fix smp_call_function_single_async() locking)
On Sun, Apr 19, 2015 at 08:01:40PM +0200, Ingo Molnar wrote:
> That's all fine and good, but why is an IPI sent to a non-existent
> CPU? It's not like we don't know which CPU is up and down.

The perf events code is trying to call smp_call_function_single() on the
non-existent CPU in perf_event_exit_cpu_context() while handling the
CPU_UP_CANCELED notification. perf_cpu_notify() handles CPU_UP_CANCELED
and CPU_DOWN_PREPARE in the same way.

(cpu_up() is tried for the non-existing CPUs because in this case what
is specified in the device tree does not match reality.)


\
 
 \ /
  Last update: 2015-04-20 18:21    [W:0.101 / U:0.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site