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| author | Ingo Molnar <mingo@elte.hu> | 2009-09-04 11:49:25 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-09-04 11:52:52 +0200 |
| commit | d7ea17a76916e456fcc78e45142c66f7fb875e3d (patch) | |
| tree | be8422a0c60216991ccd98923fe13547738ab354 /include/linux/vlynq.h | |
| parent | 18a3885fc1ffa92c2212ff0afdf033403d5b0fa0 (diff) | |
| download | blackbird-op-linux-d7ea17a76916e456fcc78e45142c66f7fb875e3d.tar.gz blackbird-op-linux-d7ea17a76916e456fcc78e45142c66f7fb875e3d.zip | |
sched: Fix dynamic power-balancing crash
This crash:
[ 1774.088275] divide error: 0000 [#1] SMP
[ 1774.100355] CPU 13
[ 1774.102498] Modules linked in:
[ 1774.105631] Pid: 30881, comm: hackbench Not tainted 2.6.31-rc8-tip-01308-g484d664-dirty #1629 X8DTN
[ 1774.114807] RIP: 0010:[<ffffffff81041c38>] [<ffffffff81041c38>]
sched_balance_self+0x19b/0x2d4
Triggers because update_group_power() modifies the sd tree and does
temporary calculations there - not considering that other CPUs
could observe intermediate values, such as the zero initial value.
Calculate it in a temporary variable instead. (we need no memory
barrier as these are all statistical values anyway)
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090904092742.GA11014@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/vlynq.h')
0 files changed, 0 insertions, 0 deletions
