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| author | Alexey Dobriyan <adobriyan@openvz.org> | 2007-02-16 12:48:11 +0300 |
|---|---|---|
| committer | Dave Jones <davej@redhat.com> | 2007-02-20 22:23:43 +0300 |
| commit | b077ffb3b767c3efb44d00b998385a9cb127255c (patch) | |
| tree | 160369b5541142afedc20a97a9c89718550cf2a3 /arch/x86_64 | |
| parent | 22f7bb0329a506f2fd61c14ce3c8bc632e08c732 (diff) | |
| download | linux-b077ffb3b767c3efb44d00b998385a9cb127255c.tar.xz | |
rdmsr_on_cpu, wrmsr_on_cpu
There was OpenVZ specific bug rendering some cpufreq drivers unusable on SMP.
In short, when cpufreq code thinks it confined itself to needed cpu by means
of set_cpus_allowed() to execute rdmsr, some "virtual cpu" feature can migrate
process to anywhere. This triggers bugons and does wrong things in general.
This got fixed by introducing rdmsr_on_cpu and wrmsr_on_cpu executing rdmsr
and wrmsr on given physical cpu by means of smp_call_function_single().
Dave Jones mentioned cpufreq might be not only user of rdmsr_on_cpu() and
wrmsr_on_cpu(), so I'm putting them into arch/{i386,x86_64}/lib/ .
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'arch/x86_64')
| -rw-r--r-- | arch/x86_64/lib/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86_64/lib/msr-on-cpu.c | 1 |
2 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86_64/lib/Makefile b/arch/x86_64/lib/Makefile index b78d4170fce2..0a43f07b0290 100644 --- a/arch/x86_64/lib/Makefile +++ b/arch/x86_64/lib/Makefile @@ -4,7 +4,7 @@ CFLAGS_csum-partial.o := -funroll-loops -obj-y := io.o iomap_copy.o +obj-y := io.o iomap_copy.o msr-on-cpu.o lib-y := csum-partial.o csum-copy.o csum-wrappers.o delay.o \ usercopy.o getuser.o putuser.o \ diff --git a/arch/x86_64/lib/msr-on-cpu.c b/arch/x86_64/lib/msr-on-cpu.c new file mode 100644 index 000000000000..47e0ec47c376 --- /dev/null +++ b/arch/x86_64/lib/msr-on-cpu.c @@ -0,0 +1 @@ +#include "../../i386/lib/msr-on-cpu.c" |