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* + arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts-by-using-smp_call_function_any.patch added to -mm tree
@ 2009-06-22 18:37 akpm
  0 siblings, 0 replies; only message in thread
From: akpm @ 2009-06-22 18:37 UTC (permalink / raw)
  To: mm-commits
  Cc: akpm, davej, efault, jaswinder, len.brown, mingo, rusty, tglx,
	venkatesh.pallipadi, yakui.zhao, yanmin_zhang


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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See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this

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 by using smp_call_function_any()
From: Andrew Morton <akpm@linux-foundation.org>

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@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@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


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