From b53e921ba1cff8453dc9a87a84052fa12d5b30bd Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Fri, 4 Apr 2008 18:11:08 -0700 Subject: generic: reduce stack pressure in sched_affinity * Modify sched_affinity functions to pass cpumask_t variables by reference instead of by value. * Use new set_cpus_allowed_ptr function. Depends on: [sched-devel]: sched: add new set_cpus_allowed_ptr function Cc: Paul Jackson Cc: Cliff Wickman Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/mcheck/mce_amd_64.c | 46 ++++++++++++++++----------------- include/linux/sched.h | 2 +- kernel/compat.c | 2 +- kernel/rcupreempt.c | 4 +-- kernel/sched.c | 5 ++-- 5 files changed, 30 insertions(+), 29 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd_64.c b/arch/x86/kernel/cpu/mcheck/mce_amd_64.c index 32671da8184..7c9a813e119 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_amd_64.c +++ b/arch/x86/kernel/cpu/mcheck/mce_amd_64.c @@ -251,18 +251,18 @@ struct threshold_attr { ssize_t(*store) (struct threshold_block *, const char *, size_t count); }; -static cpumask_t affinity_set(unsigned int cpu) +static void affinity_set(unsigned int cpu, cpumask_t *oldmask, + cpumask_t *newmask) { - cpumask_t oldmask = current->cpus_allowed; - cpumask_t newmask = CPU_MASK_NONE; - cpu_set(cpu, newmask); - set_cpus_allowed(current, newmask); - return oldmask; + *oldmask = current->cpus_allowed; + cpus_clear(*newmask); + cpu_set(cpu, *newmask); + set_cpus_allowed_ptr(current, newmask); } -static void affinity_restore(cpumask_t oldmask) +static void affinity_restore(const cpumask_t *oldmask) { - set_cpus_allowed(current, oldmask); + set_cpus_allowed_ptr(current, oldmask); } #define SHOW_FIELDS(name) \ @@ -277,15 +277,15 @@ static ssize_t store_interrupt_enable(struct threshold_block *b, const char *buf, size_t count) { char *end; - cpumask_t oldmask; + cpumask_t oldmask, newmask; unsigned long new = simple_strtoul(buf, &end, 0); if (end == buf) return -EINVAL; b->interrupt_enable = !!new; - oldmask = affinity_set(b->cpu); + affinity_set(b->cpu, &oldmask, &newmask); threshold_restart_bank(b, 0, 0); - affinity_restore(oldmask); + affinity_restore(&oldmask); return end - buf; } @@ -294,7 +294,7 @@ static ssize_t store_threshold_limit(struct threshold_block *b, const char *buf, size_t count) { char *end; - cpumask_t oldmask; + cpumask_t oldmask, newmask; u16 old; unsigned long new = simple_strtoul(buf, &end, 0); if (end == buf) @@ -306,9 +306,9 @@ static ssize_t store_threshold_limit(struct threshold_block *b, old = b->threshold_limit; b->threshold_limit = new; - oldmask = affinity_set(b->cpu); + affinity_set(b->cpu, &oldmask, &newmask); threshold_restart_bank(b, 0, old); - affinity_restore(oldmask); + affinity_restore(&oldmask); return end - buf; } @@ -316,10 +316,10 @@ static ssize_t store_threshold_limit(struct threshold_block *b, static ssize_t show_error_count(struct threshold_block *b, char *buf) { u32 high, low; - cpumask_t oldmask; - oldmask = affinity_set(b->cpu); + cpumask_t oldmask, newmask; + affinity_set(b->cpu, &oldmask, &newmask); rdmsr(b->address, low, high); - affinity_restore(oldmask); + affinity_restore(&oldmask); return sprintf(buf, "%x\n", (high & 0xFFF) - (THRESHOLD_MAX - b->threshold_limit)); } @@ -327,10 +327,10 @@ static ssize_t show_error_count(struct threshold_block *b, char *buf) static ssize_t store_error_count(struct threshold_block *b, const char *buf, size_t count) { - cpumask_t oldmask; - oldmask = affinity_set(b->cpu); + cpumask_t oldmask, newmask; + affinity_set(b->cpu, &oldmask, &newmask); threshold_restart_bank(b, 1, 0); - affinity_restore(oldmask); + affinity_restore(&oldmask); return 1; } @@ -468,7 +468,7 @@ static __cpuinit int threshold_create_bank(unsigned int cpu, unsigned int bank) { int i, err = 0; struct threshold_bank *b = NULL; - cpumask_t oldmask = CPU_MASK_NONE; + cpumask_t oldmask, newmask; char name[32]; sprintf(name, "threshold_bank%i", bank); @@ -519,10 +519,10 @@ static __cpuinit int threshold_create_bank(unsigned int cpu, unsigned int bank) per_cpu(threshold_banks, cpu)[bank] = b; - oldmask = affinity_set(cpu); + affinity_set(cpu, &oldmask, &newmask); err = allocate_threshold_blocks(cpu, bank, 0, MSR_IA32_MC0_MISC + bank * 4); - affinity_restore(oldmask); + affinity_restore(&oldmask); if (err) goto out_free; diff --git a/include/linux/sched.h b/include/linux/sched.h index be5d31752db..383502dfda1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2034,7 +2034,7 @@ static inline void arch_pick_mmap_layout(struct mm_struct *mm) } #endif -extern long sched_setaffinity(pid_t pid, cpumask_t new_mask); +extern long sched_setaffinity(pid_t pid, const cpumask_t *new_mask); extern long sched_getaffinity(pid_t pid, cpumask_t *mask); extern int sched_mc_power_savings, sched_smt_power_savings; diff --git a/kernel/compat.c b/kernel/compat.c index 9c48abfcd4a..e1ef04870c2 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -445,7 +445,7 @@ asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid, if (retval) return retval; - return sched_setaffinity(pid, new_mask); + return sched_setaffinity(pid, &new_mask); } asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len, diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c index e9517014b57..e1cdf196a51 100644 --- a/kernel/rcupreempt.c +++ b/kernel/rcupreempt.c @@ -1007,10 +1007,10 @@ void __synchronize_sched(void) if (sched_getaffinity(0, &oldmask) < 0) oldmask = cpu_possible_map; for_each_online_cpu(cpu) { - sched_setaffinity(0, cpumask_of_cpu(cpu)); + sched_setaffinity(0, &cpumask_of_cpu(cpu)); schedule(); } - sched_setaffinity(0, oldmask); + sched_setaffinity(0, &oldmask); } EXPORT_SYMBOL_GPL(__synchronize_sched); diff --git a/kernel/sched.c b/kernel/sched.c index ccc23a9cd26..1a8252385c4 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4908,9 +4908,10 @@ out_unlock: return retval; } -long sched_setaffinity(pid_t pid, cpumask_t new_mask) +long sched_setaffinity(pid_t pid, const cpumask_t *in_mask) { cpumask_t cpus_allowed; + cpumask_t new_mask = *in_mask; struct task_struct *p; int retval; @@ -4991,7 +4992,7 @@ asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len, if (retval) return retval; - return sched_setaffinity(pid, new_mask); + return sched_setaffinity(pid, &new_mask); } /* -- cgit v1.2.3