Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* '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
+27
-9
arch/x86/kernel/process.c
+27
-9
arch/x86/kernel/process.c
···
99
local_irq_enable();
100
}
101
102
-
103
-
static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c)
104
-
{
105
-
if (force_mwait)
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-
return 1;
107
-
/* Any C1 states supported? */
108
-
return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0;
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-
}
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-
111
/*
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* On SMP it's slightly faster (but much more power-consuming!)
113
* to poll the ->work.need_resched flag instead of waiting for the
···
108
{
109
local_irq_enable();
110
cpu_relax();
111
}
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113
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
···
99
local_irq_enable();
100
}
101
102
/*
103
* On SMP it's slightly faster (but much more power-consuming!)
104
* to poll the ->work.need_resched flag instead of waiting for the
···
117
{
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local_irq_enable();
119
cpu_relax();
120
+
}
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+
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+
/*
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+
* mwait selection logic:
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+
*
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+
* It depends on the CPU. For AMD CPUs that support MWAIT this is
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+
* wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings
127
+
* then depend on a clock divisor and current Pstate of the core. If
128
+
* all cores of a processor are in halt state (C1) the processor can
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+
* enter the C1E (C1 enhanced) state. If mwait is used this will never
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+
* happen.
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+
*
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+
* idle=mwait overrides this decision and forces the usage of mwait.
133
+
*/
134
+
static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c)
135
+
{
136
+
if (force_mwait)
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+
return 1;
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+
139
+
if (c->x86_vendor == X86_VENDOR_AMD) {
140
+
switch(c->x86) {
141
+
case 0x10:
142
+
case 0x11:
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+
return 0;
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+
}
145
+
}
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+
return 1;
147
}
148
149
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
+1
-1
arch/x86/mm/pat.c
+1
-1
arch/x86/mm/pat.c