The patch titled
Ignore bogus ACPI info for offline CPUs
has been added to the -mm tree. Its filename is
ignore-bogus-acpi-info-for-offline-cpus.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Ignore bogus ACPI info for offline CPUs
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Booting a SMP kernel with maxcpus=1 on a SMP system leads to a hard hang,
because ACPI ignores the maxcpus setting and sends timer broadcast info for
the offline CPUs. This results in a stuck for ever call to
smp_call_function_single() on an offline CPU.
Ignore the bogus information and print a kernel error to remind ACPI
folks to fix it.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/time/tick-broadcast.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff -puN kernel/time/tick-broadcast.c~ignore-bogus-acpi-info-for-offline-cpus kernel/time/tick-broadcast.c
--- a/kernel/time/tick-broadcast.c~ignore-bogus-acpi-info-for-offline-cpus
+++ a/kernel/time/tick-broadcast.c
@@ -243,11 +243,18 @@ void tick_broadcast_on_off(unsigned long
{
int cpu = get_cpu();
- if (cpu == *oncpu)
- tick_do_broadcast_on_off(&reason);
- else
- smp_call_function_single(*oncpu, tick_do_broadcast_on_off,
- &reason, 1, 1);
+ if (!cpu_isset(*oncpu, cpu_online_map)) {
+ printk(KERN_ERR "tick-braodcast: ignoring broadcast for "
+ "offline CPU #%d\n", *oncpu);
+ } else {
+
+ if (cpu == *oncpu)
+ tick_do_broadcast_on_off(&reason);
+ else
+ smp_call_function_single(*oncpu,
+ tick_do_broadcast_on_off,
+ &reason, 1, 1);
+ }
put_cpu();
}
_
Patches currently in -mm which might be from tglx@xxxxxxxxxxxxx are
ignore-bogus-acpi-info-for-offline-cpus.patch
drm-spinlock-initializer-cleanup.patch
s390-spinlock-initializer-cleanup.patch
i386-hpet-check-if-the-counter-works.patch
vsyscall-time-fix.patch
-
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