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Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

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* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: disable mwait for AMD family 10H/11H CPUs
  x86: fix crash on cpu hotplug on pat-incapable machines
  x86: remove mwait capability C-state check
This commit is contained in:
Linus Torvalds 2008-05-17 14:21:43 -07:00
commit 08c18964a2
2 changed files with 28 additions and 10 deletions
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36
arch/x86/kernel/process.c
View File

@ -99,15 +99,6 @@ static void mwait_idle(void)
local_irq_enable();
}
static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c)
{
if (force_mwait)
return 1;
/* Any C1 states supported? */
return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0;
}
/*
* On SMP it's slightly faster (but much more power-consuming!)
* to poll the ->work.need_resched flag instead of waiting for the
@ -119,6 +110,33 @@ static void poll_idle(void)
cpu_relax();
}
/*
* mwait selection logic:
*
* It depends on the CPU. For AMD CPUs that support MWAIT this is
* wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings
* then depend on a clock divisor and current Pstate of the core. If
* all cores of a processor are in halt state (C1) the processor can
* enter the C1E (C1 enhanced) state. If mwait is used this will never
* happen.
*
* idle=mwait overrides this decision and forces the usage of mwait.
*/
static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c)
{
if (force_mwait)
return 1;
if (c->x86_vendor == X86_VENDOR_AMD) {
switch(c->x86) {
case 0x10:
case 0x11:
return 0;
}
}
return 1;
}
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
{
static int selected;

2
arch/x86/mm/pat.c
View File

@ -28,7 +28,7 @@
#ifdef CONFIG_X86_PAT
int __read_mostly pat_wc_enabled = 1;
void __init pat_disable(char *reason)
void __cpuinit pat_disable(char *reason)
{
pat_wc_enabled = 0;
printk(KERN_INFO "%s\n", reason);