The patch titled
arch/x86/kernel/acpi/cstate.c: avoid using work_on_cpu()
has been added to the -mm tree. Its filename is
arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu.patch
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------------------------------------------------------
Subject: arch/x86/kernel/acpi/cstate.c: avoid using work_on_cpu()
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
We can use smp_call_fuction_single() here, which is faster and simpler
than work_n_cpu().
Someone ought to test 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>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/acpi/cstate.c | 36 +++++++++++++++++++++-----------
1 file changed, 24 insertions(+), 12 deletions(-)
diff -puN arch/x86/kernel/acpi/cstate.c~arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu arch/x86/kernel/acpi/cstate.c
--- a/arch/x86/kernel/acpi/cstate.c~arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu
+++ a/arch/x86/kernel/acpi/cstate.c
@@ -53,6 +53,12 @@ struct cstate_entry {
};
static struct cstate_entry *cpu_cstate_entry; /* per CPU ptr */
+/* Used for the cross-CPU calls */
+struct acpi_processor_cx_cross_cpu {
+ struct acpi_processor_cx *cx;
+ long retval;
+};
+
static short mwait_supported[ACPI_PROCESSOR_MAX_POWER];
#define MWAIT_SUBSTATE_MASK (0xf)
@@ -67,10 +73,10 @@ static short mwait_supported[ACPI_PROCES
#define NATIVE_CSTATE_BEYOND_HALT (2)
-static long acpi_processor_ffh_cstate_probe_cpu(void *_cx)
+static void acpi_processor_ffh_cstate_probe_cpu(void *_cxcc)
{
- struct acpi_processor_cx *cx = _cx;
- long retval;
+ struct acpi_processor_cx_cross_cpu *cxcc = _cxcc;
+ struct acpi_processor_cx *cx = cxcc->cx;
unsigned int eax, ebx, ecx, edx;
unsigned int edx_part;
unsigned int cstate_type; /* C-state type and not ACPI C-state type */
@@ -84,16 +90,16 @@ static long acpi_processor_ffh_cstate_pr
edx_part = edx >> (cstate_type * MWAIT_SUBSTATE_SIZE);
num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK;
- retval = 0;
+ cxcc->retval = 0;
if (num_cstate_subtype < (cx->address & MWAIT_SUBSTATE_MASK)) {
- retval = -1;
+ cxcc->retval = -1;
goto out;
}
/* mwait ecx extensions INTERRUPT_BREAK should be supported for C2/C3 */
if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
!(ecx & CPUID5_ECX_INTERRUPT_BREAK)) {
- retval = -1;
+ cxcc->retval = -1;
goto out;
}
@@ -107,7 +113,7 @@ static long acpi_processor_ffh_cstate_pr
ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x",
cx->address);
out:
- return retval;
+ return;
}
int acpi_processor_ffh_cstate_probe(unsigned int cpu,
@@ -115,6 +121,7 @@ int acpi_processor_ffh_cstate_probe(unsi
{
struct cstate_entry *percpu_entry;
struct cpuinfo_x86 *c = &cpu_data(cpu);
+ struct acpi_processor_cx_cross_cpu cxcc = { .cx = cx, };
long retval;
if (!cpu_cstate_entry || c->cpuid_level < CPUID_MWAIT_LEAF)
@@ -127,13 +134,18 @@ int acpi_processor_ffh_cstate_probe(unsi
percpu_entry->states[cx->index].eax = 0;
percpu_entry->states[cx->index].ecx = 0;
- /* Make sure we are running on right CPU */
+ /* Run acpi_processor_ffh_cstate_probe_cpu() on the target CPU */
- retval = work_on_cpu(cpu, acpi_processor_ffh_cstate_probe_cpu, cx);
+ retval = smp_call_function_single(cpu,
+ acpi_processor_ffh_cstate_probe_cpu, cx, 1);
if (retval == 0) {
- /* Use the hint in CST */
- percpu_entry->states[cx->index].eax = cx->address;
- percpu_entry->states[cx->index].ecx = MWAIT_ECX_INTERRUPT_BREAK;
+ retval = cxcc.retval;
+ if (retval == 0) {
+ /* Use the hint in CST */
+ percpu_entry->states[cx->index].eax = cx->address;
+ percpu_entry->states[cx->index].ecx =
+ MWAIT_ECX_INTERRUPT_BREAK;
+ }
}
return retval;
}
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
origin.patch
i2c-too-much-compiler-noise.patch
linux-next.patch
linux-next-git-rejects.patch
next-remove-localversion.patch
i-need-old-gcc.patch
toshiba_acpi-add-full-hotkey-support.patch
arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-using-work_on_cpu.patch
arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts.patch
arch-x86-kernel-cpu-cpufreq-acpi-cpufreqc-avoid-cross-cpu-interrupts-fix.patch
arch-x86-kernel-acpi-cstatec-avoid-using-work_on_cpu.patch
early-platform-driver-v3.patch
clocksource-pass-clocksource-to-read-callback.patch
input-bcm5974-declare-alignment-usage.patch
input-keyboard-introduce-lm8323-driver.patch
drivers-input-xpadc-improve-xbox-360-wireless-support-and-add-sysfs-interface-checkpatch-fixes.patch
input-documentation-input-xpadtxt-update-for-new-driver-functionality-checkpatch-fixes.patch
mips-cacheflush-system-call-not-returning-einval-checkpatch-fixes.patch
mtd-flex-onenand-support.patch
misdn-l1oip-reduce-stack-memory-footprint.patch
drivers-net-82596c-suppress-warnings.patch
pci-quirks-unhide-overflow-device-on-i828675p-pe-chipsets-v2.patch
raw-fix-rawctl-compat-ioctls-breakage-on-amd64-and-itanic.patch
libfs-make-simple_read_from_buffer-conventional.patch
vfs-kill-vfs_stat_fd-vfs_lstat_fd-fix.patch
xtensa-add-flat-support-checkpatch-fixes.patch
hfs-fix-memory-leak-when-unmounting-fix.patch
memcg-remove-warning-when-config_debug_vm=n-fix.patch
shmem-respect-max_lfs_filesize-fix.patch
shmem-respect-max_lfs_filesize-fix-fix.patch
shmem-respect-max_lfs_filesize-fix-2.patch
scsi-dpt_i2o-is-bust-on-ia64.patch
input-add-a-dmi-table-for-the-i8042reset-option-make-msi-wind-u-100-work.patch
mm-consolidate-init_mm-definition-fix.patch
readahead-record-mmap-read-around-states-in-file_ra_state-checkpatch-fixes.patch
readahead-introduce-context-readahead-algorithm-fix.patch
frv-duplicate-output_buffer-of-e03-checkpatch-fixes.patch
m68k-count-can-reach-51-not-50.patch
flat-fix-data-sections-alignment.patch
gru-support-for-asynchronous-gru-instructions-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
drivers-net-bonding-bond_sysfsc-suppress-uninitialized-var-warning.patch
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