Commit b53e921b authored by Mike Travis's avatar Mike Travis Committed by Ingo Molnar
Browse files

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 <pj@sgi.com>
Cc: Cliff Wickman <cpw@sgi.com>
Signed-off-by: default avatarMike Travis <travis@sgi.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent f9a86fcb

arch/x86/kernel/cpu/mcheck/mce_amd_64.c

+23 −23
Original line number Diff line number Diff line
@@ -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;

include/linux/sched.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

kernel/compat.c

+1 −1
Original line number Diff line number Diff line
@@ -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,

kernel/rcupreempt.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

kernel/sched.c

+3 −2
Original line number Diff line number Diff line
@@ -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);

}



/*

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