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smp,cpumask: introduce on_each_cpu_cond_mask

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Introduce a variant of on_each_cpu_cond that iterates only over the
CPUs in a cpumask, in order to avoid making callbacks for every single
CPU in the system when we only need to test a subset.

Cc: npiggin@gmail.com
Cc: mingo@kernel.org
Cc: will.deacon@arm.com
Cc: songliubraving@fb.com
Cc: kernel-team@fb.com
Cc: hpa@zytor.com
Cc: luto@kernel.org
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180926035844.1420-5-riel@surriel.com
This commit is contained in:
Rik van Riel 2018-09-25 23:58:41 -04:00 committed by Peter Zijlstra
parent c3f7f2c7eb
commit 7d49b28a80
3 changed files with 28 additions and 7 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
include/linux/smp.h
View file

@ -53,6 +53,10 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags);
void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags, const struct cpumask *mask);
int smp_call_function_single_async(int cpu, call_single_data_t *csd);
#ifdef CONFIG_SMP

17
kernel/smp.c
View file

@ -669,9 +669,9 @@ EXPORT_SYMBOL(on_each_cpu_mask);
* You must not call this function with disabled interrupts or
* from a hardware interrupt handler or from a bottom half handler.
*/
void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags)
gfp_t gfp_flags, const struct cpumask *mask)
{
cpumask_var_t cpus;
int cpu, ret;
@ -680,7 +680,7 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
if (likely(zalloc_cpumask_var(&cpus, (gfp_flags|__GFP_NOWARN)))) {
preempt_disable();
for_each_online_cpu(cpu)
for_each_cpu(cpu, mask)
if (cond_func(cpu, info))
__cpumask_set_cpu(cpu, cpus);
on_each_cpu_mask(cpus, func, info, wait);
@ -692,7 +692,7 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
* just have to IPI them one by one.
*/
preempt_disable();
for_each_online_cpu(cpu)
for_each_cpu(cpu, mask)
if (cond_func(cpu, info)) {
ret = smp_call_function_single(cpu, func,
info, wait);
@ -701,6 +701,15 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
preempt_enable();
}
}
EXPORT_SYMBOL(on_each_cpu_cond_mask);
void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags)
{
on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags,
cpu_online_mask);
}
EXPORT_SYMBOL(on_each_cpu_cond);
static void do_nothing(void *unused)

14
kernel/up.c
View file

@ -68,9 +68,9 @@ EXPORT_SYMBOL(on_each_cpu_mask);
* Preemption is disabled here to make sure the cond_func is called under the
* same condtions in UP and SMP.
*/
void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags)
void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags, const struct cpumask *mask)
{
unsigned long flags;
@ -82,6 +82,14 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
}
preempt_enable();
}
EXPORT_SYMBOL(on_each_cpu_cond_mask);
void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags)
{
on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags, NULL);
}
EXPORT_SYMBOL(on_each_cpu_cond);
int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)