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| author | Peter Zijlstra <peterz@infradead.org> | 2016-05-09 10:38:41 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-09-30 11:03:26 +0200 |
| commit | 1b568f0aabf280555125bc7cefc08321ff0ebaba (patch) | |
| tree | 5ca491fb2b8a7ff46af700bc64c2d83cea68eabb /kernel/sched/fair.c | |
| parent | 10e2f1acd0106c05229f94c70a344ce3a2c8008b (diff) | |
| download | linux-1b568f0aabf280555125bc7cefc08321ff0ebaba.tar.bz2 | |
sched/core: Optimize SCHED_SMT
Avoid pointless SCHED_SMT code when running on !SMT hardware.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6b41589c41e4..87caf2bd26f0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5357,7 +5357,7 @@ static inline bool test_idle_cores(int cpu, bool def) * Since SMT siblings share all cache levels, inspecting this limited remote * state should be fairly cheap. */ -void update_idle_core(struct rq *rq) +void __update_idle_core(struct rq *rq) { int core = cpu_of(rq); int cpu; @@ -5389,6 +5389,9 @@ static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask); int core, cpu, wrap; + if (!static_branch_likely(&sched_smt_present)) + return -1; + if (!test_idle_cores(target, false)) return -1; @@ -5422,6 +5425,9 @@ static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int t { int cpu; + if (!static_branch_likely(&sched_smt_present)) + return -1; + for_each_cpu(cpu, cpu_smt_mask(target)) { if (!cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) continue; |