linux/arch
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
..
alpha Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
arm Replace all DMA_nBIT_MASK macro with DMA_BIT_MASK(n) 2009-04-13 15:04:33 -07:00
avr32 dma-mapping: replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32) 2009-04-07 08:31:11 -07:00
blackfin tty: Blackin CTS/RTS 2009-04-07 08:44:05 -07:00
cris tty: Use the generic RS485 ioctl on CRIS 2009-04-07 08:44:05 -07:00
frv FRV: Move to arch/frv/include/asm/ 2009-04-10 01:48:06 +01:00
h8300 Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
ia64 Replace all DMA_nBIT_MASK macro with DMA_BIT_MASK(n) 2009-04-13 15:04:33 -07:00
m32r Simplify copy_thread() 2009-04-02 19:04:51 -07:00
m68k Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
m68knommu Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2009-04-03 09:44:58 -07:00
microblaze microblaze: remove duplicated #include's 2009-04-14 11:09:15 +02:00
mips Merge branch 'next' into for-linus 2009-04-08 00:00:33 -07:00
mn10300 Separate out the proc- and unit-specific header directories from the general 2009-04-10 14:33:48 +01:00
parisc Merge git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6 2009-04-03 09:52:04 -07:00
powerpc parport_pc: Fix build failure drivers/parport/parport_pc.c for powerpc 2009-04-14 08:48:50 -07:00
s390 mutex: have non-spinning mutexes on s390 by default 2009-04-09 19:28:24 +02:00
sh sh: Add in PCI bus for DMA API debugging. 2009-04-14 15:23:40 +09:00
sparc parport: Fix various uses of parport_pc 2009-04-14 08:48:50 -07:00
um Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
x86 acpi-cpufreq: fix 'smp_call_function_many()' confusion 2009-04-15 08:41:16 -07:00
xtensa Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
.gitignore
Kconfig mutex: have non-spinning mutexes on s390 by default 2009-04-09 19:28:24 +02:00