diff options
| author |   Ingo Molnar <mingo@elte.hu> | 2007-03-07 18:12:31 +0100 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-03-07 10:07:24 -0800 |
| commit | d04f41e35343f1d788551fd3f753f51794f4afcf (patch) | |
| tree | 50f22b1deab312476254868e8ec8c0c592c3d3e0 /arch/x86_64/kernel/smpboot.c | |
| parent | Linux 2.6.21-rc3 (diff) | |
| download | linux-dev-d04f41e35343f1d788551fd3f753f51794f4afcf.tar.xz linux-dev-d04f41e35343f1d788551fd3f753f51794f4afcf.zip | |
[PATCH] CPU hotplug: call check_tsc_sync_source() with irqs off
check_tsc_sync_source() depends on being called with irqs disabled (it
checks whether the TSC is coherent across two specific CPUs). This is
incidentally true during bootup, but not during cpu hotplug __cpu_up().
This got found via smp_processor_id() debugging.
disable irqs explicitly and remove the unconditional enabling of
interrupts. Add touch_nmi_watchdog() to the cpu_online_map busy loop.
this bug is present both on i386 and on x86_64.
Reported-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86_64/kernel/smpboot.c')
| -rw-r--r-- | arch/x86_64/kernel/smpboot.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c index 35443729aad8..cd4643a37022 100644 --- a/arch/x86_64/kernel/smpboot.c +++ b/arch/x86_64/kernel/smpboot.c @@ -923,8 +923,9 @@ void __init smp_prepare_boot_cpu(void) */ int __cpuinit __cpu_up(unsigned int cpu) { - int err; int apicid = cpu_present_to_apicid(cpu); + unsigned long flags; + int err; WARN_ON(irqs_disabled()); @@ -958,7 +959,9 @@ int __cpuinit __cpu_up(unsigned int cpu) /* * Make sure and check TSC sync: */ + local_irq_save(flags); check_tsc_sync_source(cpu); + local_irq_restore(flags); while (!cpu_isset(cpu, cpu_online_map)) cpu_relax(); |