[PATCH openEuler-5.10 12/64] tick/nohz: Call tick_nohz_task_switch() with interrupts disabled

From: Peter Zijlstra peterz@infradead.org

mainline inclusion from mainline-5.14-rc1 commit 0fdcccfafcffac70b452b3127cc3d981f0117655 category: feature feature: Deep isolation bugzilla: https://gitee.com/openeuler/kernel/issues/I4N00D CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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Call tick_nohz_task_switch() slightly earlier after the context switch to benefit from disabled IRQs. This way the function doesn't need to disable them once more.

Signed-off-by: Peter Zijlstra peterz@infradead.org Signed-off-by: Frederic Weisbecker frederic@kernel.org Signed-off-by: Ingo Molnar mingo@kernel.org Link: https://lore.kernel.org/r/20210512232924.150322-10-frederic@kernel.org Signed-off-by: Yunfeng Ye yeyunfeng@huawei.com Reviewed-by: liu chao liuchao173@huawei.com Reviewed-by: Chen Hui judy.chenhui@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- kernel/sched/core.c | 2 +- kernel/time/tick-sched.c | 7 +------ 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c880f5f4e6bb..93961898567b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3652,6 +3652,7 @@ static struct rq *finish_task_switch(struct task_struct *prev) vtime_task_switch(prev); perf_event_task_sched_in(prev, current); finish_task(prev); + tick_nohz_task_switch(); finish_lock_switch(rq); finish_arch_post_lock_switch(); kcov_finish_switch(current); @@ -3689,7 +3690,6 @@ static struct rq *finish_task_switch(struct task_struct *prev) put_task_struct_rcu_user(prev); }

- tick_nohz_task_switch(); return rq; }

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index c5c1287f0d2a..49423dffdfc3 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -467,13 +467,10 @@ void tick_nohz_dep_clear_signal(struct signal_struct *sig, enum tick_dep_bits bi */ void __tick_nohz_task_switch(void) { - unsigned long flags; struct tick_sched *ts;

- local_irq_save(flags); - if (!tick_nohz_full_cpu(smp_processor_id())) - goto out; + return;

ts = this_cpu_ptr(&tick_cpu_sched);

@@ -482,8 +479,6 @@ void __tick_nohz_task_switch(void) atomic_read(&current->signal->tick_dep_mask)) tick_nohz_full_kick(); } -out: - local_irq_restore(flags); }

/* Get the boot-time nohz CPU list from the kernel parameters. */