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.
Signed-off-by: Rik van Riel <r...@surriel.com> --- include/linux/smp.h | 4 ++++ kernel/smp.c | 17 +++++++++++++---- kernel/up.c | 14 +++++++++++--- 3 files changed, 28 insertions(+), 7 deletions(-) diff --git a/include/linux/smp.h b/include/linux/smp.h index 9fb239e12b82..a56f08ff3097 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -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 diff --git a/kernel/smp.c b/kernel/smp.c index 2dbc842dd385..f4cf1b0bb3b8 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -667,9 +667,9 @@ 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; @@ -678,7 +678,7 @@ 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); @@ -690,7 +690,7 @@ 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); @@ -699,6 +699,15 @@ 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) diff --git a/kernel/up.c b/kernel/up.c index 42c46bf3e0a5..ff536f9cc8a2 100644 --- a/kernel/up.c +++ b/kernel/up.c @@ -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) -- 2.14.4