smp,cpumask: introduce on_each_cpu_cond_mask

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

1 files changed, 4 insertions, 0 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