From b8cbe7e82ec8b55d7bbdde66fc69e788fde00dc6 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 3 Nov 2009 14:57:56 +1030 Subject: [PATCH] [CPUFREQ] cpumask: don't put a cpumask on the stack in x86...cpufreq/powernow-k8.c It's still mugging the current process's cpumask, but as comment in 1ff6e97f1d says, it's not a trivial fix. So, at least we can use a cpumask_var_t to do the Wrong Thing the Right Way :) Signed-off-by: Rusty Russell To: cpufreq@vger.kernel.org Cc: Mark Langsdorf Signed-off-by: Dave Jones --- arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c index 3f12dabeab52..f30d25383940 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c @@ -1118,7 +1118,7 @@ static int transition_frequency_pstate(struct powernow_k8_data *data, static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsigned relation) { - cpumask_t oldmask; + cpumask_var_t oldmask; struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); u32 checkfid; u32 checkvid; @@ -1131,9 +1131,13 @@ static int powernowk8_target(struct cpufreq_policy *pol, checkfid = data->currfid; checkvid = data->currvid; - /* only run on specific CPU from here on */ - oldmask = current->cpus_allowed; - set_cpus_allowed_ptr(current, &cpumask_of_cpu(pol->cpu)); + /* only run on specific CPU from here on. */ + /* This is poor form: use a workqueue or smp_call_function_single */ + if (!alloc_cpumask_var(&oldmask, GFP_KERNEL)) + return -ENOMEM; + + cpumask_copy(oldmask, tsk_cpumask(current)); + set_cpus_allowed_ptr(current, cpumask_of(pol->cpu)); if (smp_processor_id() != pol->cpu) { printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu); @@ -1193,7 +1197,8 @@ static int powernowk8_target(struct cpufreq_policy *pol, ret = 0; err_out: - set_cpus_allowed_ptr(current, &oldmask); + set_cpus_allowed_ptr(current, oldmask); + free_cpumask_var(oldmask); return ret; } -- 2.20.1