diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2012-03-26 11:16:15 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-03-27 12:50:10 (GMT) |
| commit | bc758133ed73d4b06952bec21da23e28e62bf3ba (patch) | |
| tree | c7d2a8cec16533e7d3b3896f9fdc7c0350b8a041 | |
| parent | 6c16a6dcb05e51ace340ff7bc6dbe647f1593528 (diff) | |
| download | linux-bc758133ed73d4b06952bec21da23e28e62bf3ba.tar.xz | |
sched/x86/smp: Do not enable IRQs over calibrate_delay()
We should not ever enable IRQs until we're fully set up. This opens up
a window where interrupts can hit the cpu and interrupts can do
wakeups, wakeups need state that isn't set-up yet, in particular this
cpu isn't elegible to run tasks, so if any cpu-affine task that got
created in CPU_UP_PREPARE manages to get a wakeup, its affinity mask
will get broken and we'll run into lots of 'interesting' problems.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-yaezmlbriluh166tfkgni22m@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 58f7816..89571a0 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -219,14 +219,9 @@ static void __cpuinit smp_callin(void) * Update loops_per_jiffy in cpu_data. Previous call to * smp_store_cpu_info() stored a value that is close but not as * accurate as the value just calculated. - * - * Need to enable IRQs because it can take longer and then - * the NMI watchdog might kill us. */ - local_irq_enable(); calibrate_delay(); cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy; - local_irq_disable(); pr_debug("Stack at about %p\n", &cpuid); /* |