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x86: Remove cpumask games in x86/kernel/cpu/intel_cacheinfo.c

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Impact: remove cpumask_t from stack.

We should not try to save and restore cpus_allowed on current.

We can't use work_on_cpu() here, since it's in the hotplug cpu path
(if anyone else tries to get the hotplug lock from a workqueue we
could deadlock against them).

Fortunately, we can just use smp_call_function_single() since the
function can run from an interrupt.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
This commit is contained in:
Mike Travis 2008-12-16 17:34:03 -08:00
parent 1de88cd4a3
commit b2bb855491
1 changed files with 21 additions and 24 deletions
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45
arch/x86/kernel/cpu/intel_cacheinfo.c
View file

@ -534,12 +534,29 @@ static void __cpuinit free_cache_attributes(unsigned int cpu)
per_cpu(cpuid4_info, cpu) = NULL;
}
static void get_cpu_leaves(void *_retval)
{
int j, *retval = _retval, cpu = smp_processor_id();
/* Do cpuid and store the results */
for (j = 0; j < num_cache_leaves; j++) {
struct _cpuid4_info *this_leaf;
this_leaf = CPUID4_INFO_IDX(cpu, j);
*retval = cpuid4_cache_lookup(j, this_leaf);
if (unlikely(*retval < 0)) {
int i;
for (i = 0; i < j; i++)
cache_remove_shared_cpu_map(cpu, i);
break;
}
cache_shared_cpu_map_setup(cpu, j);
}
}
static int __cpuinit detect_cache_attributes(unsigned int cpu)
{
struct _cpuid4_info *this_leaf;
unsigned long j;
int retval;
cpumask_t oldmask;
if (num_cache_leaves == 0)
return -ENOENT;
@ -549,27 +566,7 @@ static int __cpuinit detect_cache_attributes(unsigned int cpu)
if (per_cpu(cpuid4_info, cpu) == NULL)
return -ENOMEM;
oldmask = current->cpus_allowed;
retval = set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
if (retval)
goto out;
/* Do cpuid and store the results */
for (j = 0; j < num_cache_leaves; j++) {
this_leaf = CPUID4_INFO_IDX(cpu, j);
retval = cpuid4_cache_lookup(j, this_leaf);
if (unlikely(retval < 0)) {
int i;
for (i = 0; i < j; i++)
cache_remove_shared_cpu_map(cpu, i);
break;
}
cache_shared_cpu_map_setup(cpu, j);
}
set_cpus_allowed_ptr(current, &oldmask);
out:
smp_call_function_single(cpu, get_cpu_leaves, &retval, true);
if (retval) {
kfree(per_cpu(cpuid4_info, cpu));
per_cpu(cpuid4_info, cpu) = NULL;