[PATCH 55/79] [PATCH] calibrate delay with irqs enabled

From: Glauber de Oliveira Costa
Date: Wed Mar 19 2008 - 16:05:50 EST


From: Glauber Costa <gcosta@xxxxxxxxxx>

We do it to make it close to x86_64. The later needs it,
otherwise the nmi watchdog can get into the scene and kill us
with a hammer.

Enabling irqs here used to trigger a bug in i386. This is because
time irq handling relies upon structures that are only initialized
after smp initcalls (More precisely, it will find
per_cpu(hrtimer_bases, cpu)->cb_pending list not initialized and crash)

Signed-off-by: Glauber Costa <gcosta@xxxxxxxxxx>
---
arch/x86/kernel/smpboot_32.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/smpboot_32.c b/arch/x86/kernel/smpboot_32.c
index dbfaeb3..bd2f886 100644
--- a/arch/x86/kernel/smpboot_32.c
+++ b/arch/x86/kernel/smpboot_32.c
@@ -167,7 +167,9 @@ static void __cpuinit smp_callin(void)
/*
* Get our bogomips.
*/
+ local_irq_enable();
calibrate_delay();
+ local_irq_disable();
Dprintk("Stack at about %p\n",&cpuid);

/*
--
1.5.0.6

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