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Subject[PATCH 8/14] 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 <rusty@rustcorp.com.au>
To: cpufreq@vger.kernel.org
Cc: Mark Langsdorf <mark.langsdorf@amd.com>
Cc: Dave Jones <davej@redhat.com>
---
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
--- 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(s
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 cpuf
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 cpuf
ret = 0;

err_out:
- set_cpus_allowed_ptr(current, &oldmask);
+ set_cpus_allowed_ptr(current, oldmask);
+ free_cpumask_var(oldmask);
return ret;
}



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