From b2bb85549134c005e997e5a7ed303bda6a1ae738 Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Tue, 16 Dec 2008 17:34:03 -0800 Subject: [PATCH] x86: Remove cpumask games in x86/kernel/cpu/intel_cacheinfo.c 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 Signed-off-by: Mike Travis Cc: Ingo Molnar Cc: Oleg Nesterov --- arch/x86/kernel/cpu/intel_cacheinfo.c | 45 +++++++++++++-------------- 1 file changed, 21 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c index 43ea612d3e9d..fb7f946cb65e 100644 --- a/arch/x86/kernel/cpu/intel_cacheinfo.c +++ b/arch/x86/kernel/cpu/intel_cacheinfo.c @@ -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;