[to-be-updated] arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts.patch removed from -mm tree

[to-be-updated] arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts.patch removed from -mm tree

[akpm]

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@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>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
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
@@ -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@linux-foundation.org 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