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3 Коммитов

Автор SHA1 Сообщение Дата
Rudolf Marek 4e9baad8f5 i386: Add safe variants of rdmsr_on_cpu and wrmsr_on_cpu
Add safe (exception handled) variants of rdmsr_on_cpu and wrmsr_on_cpu.
You should use these when the target MSR may not actually exist, as
doing so could trigger an exception which the regular functions do not
handle. The safe variants are slower, though.

The upcoming coretemp hardware monitoring driver will need this.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Cc: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-08 17:22:01 +02:00
Adrian Bunk b44755cfaa {rd,wr}msr_on_cpu SMP=n optimization
Let's save a few bytes in the CONFIG_SMP=n case.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2007-02-20 14:29:37 -05:00
Alexey Dobriyan b077ffb3b7 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>
2007-02-20 14:23:43 -05:00