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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-09-20 14:46:13 -0400 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-09-20 14:46:13 -0400 |
| commit | 78ba6223a14eac73a1fbfc35bd456348171bffc6 (patch) | |
| tree | db50b17e03f3772443798415654c873d769a54ec /arch/x86/kernel/cpu | |
| parent | f392cbf75615e9d8cb90ef5ffb8d4e752b7be3c7 (diff) | |
| parent | 04aa37b5f943920017ad094e776cd5514b1a9246 (diff) | |
Merge commit 'v3.0.4' into linaro-3.0linux-linaro-3.0-2011.09-0
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 10 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/main.c | 23 |
2 files changed, 28 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index da0d779ecd9..ed6086eedf1 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -465,11 +465,11 @@ static void __cpuinit init_intel(struct cpuinfo_x86 *c) u64 epb; rdmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb); - if ((epb & 0xF) == 0) { - printk_once(KERN_WARNING, "x86: updated energy_perf_bias" - " to 'normal' from 'performance'\n" - "You can view and update epb via utility," - " such as x86_energy_perf_policy(8)\n"); + if ((epb & 0xF) == ENERGY_PERF_BIAS_PERFORMANCE) { + printk_once(KERN_WARNING "ENERGY_PERF_BIAS:" + " Set to 'normal', was 'performance'\n" + "ENERGY_PERF_BIAS: View and update with" + " x86_energy_perf_policy(8)\n"); epb = (epb & ~0xF) | ENERGY_PERF_BIAS_NORMAL; wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, epb); } diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c index 929739a653d..3d17bc7f06e 100644 --- a/arch/x86/kernel/cpu/mtrr/main.c +++ b/arch/x86/kernel/cpu/mtrr/main.c @@ -248,6 +248,25 @@ set_mtrr(unsigned int reg, unsigned long base, unsigned long size, mtrr_type typ unsigned long flags; int cpu; +#ifdef CONFIG_SMP + /* + * If this cpu is not yet active, we are in the cpu online path. There + * can be no stop_machine() in parallel, as stop machine ensures this + * by using get_online_cpus(). We can skip taking the stop_cpus_mutex, + * as we don't need it and also we can't afford to block while waiting + * for the mutex. + * + * If this cpu is active, we need to prevent stop_machine() happening + * in parallel by taking the stop cpus mutex. + * + * Also, this is called in the context of cpu online path or in the + * context where cpu hotplug is prevented. So checking the active status + * of the raw_smp_processor_id() is safe. + */ + if (cpu_active(raw_smp_processor_id())) + mutex_lock(&stop_cpus_mutex); +#endif + preempt_disable(); data.smp_reg = reg; @@ -330,6 +349,10 @@ set_mtrr(unsigned int reg, unsigned long base, unsigned long size, mtrr_type typ local_irq_restore(flags); preempt_enable(); +#ifdef CONFIG_SMP + if (cpu_active(raw_smp_processor_id())) + mutex_unlock(&stop_cpus_mutex); +#endif } /** |