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authorRussell King <rmk+kernel@arm.linux.org.uk>2010-12-02 09:53:54 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-12-20 15:08:26 +0000
commit28e18293cf0f8d23a0950d7b1d2212d11af494dc (patch)
treefbd27f23bbd1b85ef7b06cf4b5f733f46a929044 /arch
parent0eb0511d176534674600a1986c3c766756288908 (diff)
downloadop-kernel-dev-28e18293cf0f8d23a0950d7b1d2212d11af494dc.zip
op-kernel-dev-28e18293cf0f8d23a0950d7b1d2212d11af494dc.tar.gz
ARM: SMP: ensure smp_send_stop() waits for CPUs to stop
Wait for CPUs to indicate that they've stopped, after sending the stop IPI, rather than blindly continuing on and hoping that they've stopped in time. Print a warning if we fail to stop the other CPUs. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/kernel/smp.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 1de3e13..64f2d19 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -575,10 +575,22 @@ void smp_send_reschedule(int cpu)
void smp_send_stop(void)
{
- cpumask_t mask = cpu_online_map;
- cpu_clear(smp_processor_id(), mask);
- if (!cpus_empty(mask))
+ unsigned long timeout;
+
+ if (num_online_cpus() > 1) {
+ cpumask_t mask = cpu_online_map;
+ cpu_clear(smp_processor_id(), mask);
+
smp_cross_call(&mask, IPI_CPU_STOP);
+ }
+
+ /* Wait up to one second for other CPUs to stop */
+ timeout = USEC_PER_SEC;
+ while (num_online_cpus() > 1 && timeout--)
+ udelay(1);
+
+ if (num_online_cpus() > 1)
+ pr_warning("SMP: failed to stop secondary CPUs\n");
}
/*
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