sched/debug: Optimize sched_domain sysctl generation

Currently we unconditionally destroy all sysctl bits and regenerate
them after we've rebuild the domains (even if that rebuild is a
no-op).

And since we unconditionally (re)build the sysctl for all possible
CPUs, onlining all CPUs gets us O(n^2) time. Instead change this to
only rebuild the bits for CPUs we've actually installed new domains
on.

Reported-by: Ofer Levi(SW) <oferle@mellanox.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra
2017-08-10 17:10:26 +02:00
committed by Ingo Molnar
parent 09e0dd8e0f
commit bbdacdfed2
3 changed files with 59 additions and 14 deletions

View File

@@ -1120,11 +1120,15 @@ extern int group_balance_cpu(struct sched_group *sg);
#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
void register_sched_domain_sysctl(void);
void dirty_sched_domain_sysctl(int cpu);
void unregister_sched_domain_sysctl(void);
#else
static inline void register_sched_domain_sysctl(void)
{
}
static inline void dirty_sched_domain_sysctl(int cpu)
{
}
static inline void unregister_sched_domain_sysctl(void)
{
}