linux/arch/x86
Linus Torvalds ea34f43a07 acpi-cpufreq: fix 'smp_call_function_many()' confusion
It turns out that 'smp_call_function_many()' doesn't work at all like
'smp_call_function_single()', and my change to Andrew's patch to use it
rather than a loop over all CPU's acpi-cpufreq doesn't work.

My bad.

'smp_call_function_many()' has two "features" (aka "documented bugs"):

 (a) it needs to be called with preemption disabled, because it uses
     smp_processor_id() without guarding the CPU lookup with 'get_cpu()'
     and 'put_cpu()' like the 'single' variant does.

 (b) even if the current CPU is part of the CPU mask, it won't do the
     call on that CPU.

Still, we're better off trying to use 'smp_call_function_many()' than
looping over CPU's, since it at least in theory allows us to use a
broadcast IPI and do it all in parallel.  So let's just work around the
silly semantic bugs in that function.

Reported-and-tested-by: Ali Gholami Rudi <ali@rudi.ir>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-15 08:41:16 -07:00
..
boot x86, setup: un-resequence mode setting for VGA 80x34 and 80x60 modes 2009-04-07 10:59:25 -07:00
configs Merge branches 'x86/apic', 'x86/defconfig', 'x86/memtest', 'x86/mm' and 'linus' into x86/core 2009-02-26 06:31:32 +01:00
crypto
ia32 preadv/pwritev: Add preadv and pwritev system calls. 2009-04-02 19:05:08 -07:00
include/asm Merge branch 'for-rc1/xen/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2009-04-13 15:30:20 -07:00
kernel acpi-cpufreq: fix 'smp_call_function_many()' confusion 2009-04-15 08:41:16 -07:00
kvm Merge branch 'tracing/core-v2' into tracing-for-linus 2009-04-02 00:49:02 +02:00
lguest Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest-and-virtio 2009-03-30 17:57:39 -07:00
lib x86: memcpy, clean up 2009-03-12 12:21:17 +01:00
math-emu Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2 2009-03-27 17:28:43 +01:00
mm x86: fix wrong section of pat_disable & make it static 2009-04-12 12:34:23 +02:00
oprofile cpumask: x86: convert cpu_sibling_map/cpu_core_map to cpumask_var_t 2009-03-13 14:49:50 +10:30
pci x86, PAT: Remove duplicate memtype reserve in pci mmap 2009-04-03 14:43:29 -07:00
power x86: disable stack-protector for __restore_processor_state() 2009-04-03 19:48:41 +02:00
vdso
video
xen Merge branch 'for-rc1/xen/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2009-04-13 15:30:20 -07:00
Kconfig x86, intel-iommu: fix X2APIC && !ACPI build failure 2009-04-07 08:22:46 +02:00
Kconfig.cpu x86/centaur: merge 32 & 64 bit version 2009-03-14 16:27:29 +01:00
Kconfig.debug generic debug pagealloc: build fix 2009-04-02 19:04:48 -07:00
Makefile x86: use targets in the boot Makefile instead of CLEAN_FILES 2009-03-12 13:43:14 -07:00
Makefile_32.cpu