Messages in this thread | | | Subject | Re: [patch for 2.6.30 2/2] arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c: avoid cross-CPU interrupts | From | Jaswinder Singh Rajput <> | Date | Sat, 11 Apr 2009 12:07:11 +0530 |
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On Fri, 2009-04-10 at 23:17 -0700, akpm@linux-foundation.org wrote: > From: Andrew Morton <akpm@linux-foundation.org> > > In drv_read(), check to see whether we can run the rdmsr() on the current > CPU. If so, do that. So smp_call_function_single() can avoid the IPI. > > Arguably, cpumask_any() should do this. > > Cc: Rusty Russell <rusty@rustcorp.com.au> > Cc: Ingo Molnar <mingo@elte.hu> > Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> > Cc: Len Brown <len.brown@intel.com> > Cc: Zhao Yakui <yakui.zhao@intel.com> > Cc: Dave Jones <davej@redhat.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Tested-by: Mike Galbraith <efault@gmx.de> > Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > --- > > arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff -puN arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c~arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c~arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts > +++ a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c > @@ -197,9 +197,22 @@ static void do_drv_write(void *_cmd) > > static void drv_read(struct drv_cmd *cmd) > { > - cmd->val = 0; > + int target_cpu; /* The CPU on which to perform thr rdmsr() */
+ int target_cpu; /* The CPU on which to perform the rdmsr() */
-- JSR
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