The patch titled
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c: avoid cross-CPU interrupts by using smp_call_function_any()
has been added to the -mm tree. Its filename is
arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts-by-using-smp_call_function_any.patch
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Subject: arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c: avoid cross-CPU interrupts by using smp_call_function_any()
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Presently acpi-cpufreq will perform the MSR read on the first CPU in the
mask. That's inefficient if that CPU differs from the current CPU.
Because we have to perform a cross-CPU call, but we could have run the
rdmsr on the current CPU.
So switch to using the new smp_call_function_any(), whcih will perform the
call on the current CPU if that CPU is present in the mask (it is).
Cc: "Zhang, Yanmin" <yanmin_zhang@xxxxxxxxxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jaswinder Singh Rajput <jaswinder@xxxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Cc: Zhao Yakui <yakui.zhao@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff -puN arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c~arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts-by-using-smp_call_function_any 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-by-using-smp_call_function_any
+++ a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -197,9 +197,11 @@ static void do_drv_write(void *_cmd)
static void drv_read(struct drv_cmd *cmd)
{
+ int err;
cmd->val = 0;
- smp_call_function_single(cpumask_any(cmd->mask), do_drv_read, cmd, 1);
+ err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
+ WARN_ON_ONCE(err); /* smp_call_function_any() was buggy? */
}
static void drv_write(struct drv_cmd *cmd)
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
origin.patch
linux-next.patch
next-remove-localversion.patch
i-need-old-gcc.patch
arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts-by-using-smp_call_function_any.patch
arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts.patch
devres-warn-and-return-dont-crash-on-device_del-of-uninitialized-device.patch
input-drivers-input-xpadc-improve-xbox-360-wireless-support-and-add-sysfs-interface.patch
input-documentation-input-xpadtxt-update-for-new-driver-functionality.patch
3x59x-fix-pci-resource-management-checkpatch-fixes.patch
jsm-clean-up-serial-jsm-correctly-support-4-8-port-boards.patch
raw-fix-rawctl-compat-ioctls-breakage-on-amd64-and-itanic.patch
libfs-make-simple_read_from_buffer-conventional.patch
drivers-rtc-rtc-cmosc-cmos_init-dont-ignore-pnp_register_driver-return-value.patch
readahead-add-blk_run_backing_dev-fix.patch
readahead-add-blk_run_backing_dev-fix-fix-2.patch
frv-duplicate-output_buffer-of-e03-checkpatch-fixes.patch
m68k-count-can-reach-51-not-50.patch
arch-m68k-include-asm-motorola_pgalloch-fix-kunmap-arg.patch
net-netfilter-ipvs-ip_vs_wrrc-use-lib-gcdc-fix.patch
reiser4-export-remove_from_page_cache-fix.patch
reiser4.patch
reiser4-remove-simple_prepare_write-usage-checkpatch-fixes.patch
slab-leaks3-default-y.patch
put_bh-debug.patch
shrink_slab-handle-bad-shrinkers.patch
getblk-handle-2tb-devices.patch
getblk-handle-2tb-devices-fix.patch
undeprecate-pci_find_device.patch
notify_change-callers-must-hold-i_mutex.patch
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