The patch titled
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c: avoid cross-CPU interrupts
has been removed from the -mm tree. Its filename was
arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts.patch
This patch was dropped because an updated version will be merged
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c: avoid cross-CPU interrupts
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: Zhao Yakui <yakui.zhao@xxxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Mike Galbraith <efault@xxxxxx>
Cc: "Zhang, Yanmin" <yanmin_zhang@xxxxxxxxxxxxxxx>
Cc: Jaswinder Singh Rajput <jaswinder@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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
@@ -201,9 +201,22 @@ 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 the rdmsr() */
+ int this_cpu;
- smp_call_function_single(cpumask_any(cmd->mask), do_drv_read, cmd, 1);
+ /*
+ * If the current CPU is in cmd->mask then run the rdmsr() on this
+ * CPU to avoid the cross-cpu interrupt.
+ */
+ this_cpu = get_cpu();
+ if (cpu_isset(this_cpu, *(cmd->mask)))
+ target_cpu = this_cpu;
+ else
+ target_cpu = cpumask_any(cmd->mask);
+
+ cmd->val = 0;
+ smp_call_function_single(target_cpu, do_drv_read, cmd, 1);
+ put_cpu();
}
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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