Thread (12 messages) 12 messages, 3 authors, 2022-02-08

Re: [PATCH v2 5/7] sched/preempt: add PREEMPT_DYNAMIC using static keys

From: Frederic Weisbecker <frederic@kernel.org>
Date: 2022-02-07 12:09:38
Also in: lkml

On Fri, Feb 04, 2022 at 03:05:55PM +0000, Mark Rutland wrote:
quoted hunk ↗ jump to hunk
diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
index dfd84c59b144..141952f4fee8 100644
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@ -456,13 +456,19 @@ irqentry_state_t noinstr irqentry_enter(struct pt_regs *regs);
  */
 void raw_irqentry_exit_cond_resched(void);
 #ifdef CONFIG_PREEMPT_DYNAMIC
+#if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
 #define irqentry_exit_cond_resched_dynamic_enabled	raw_irqentry_exit_cond_resched
 #define irqentry_exit_cond_resched_dynamic_disabled	NULL
 DECLARE_STATIC_CALL(irqentry_exit_cond_resched, raw_irqentry_exit_cond_resched);
 #define irqentry_exit_cond_resched()	static_call(irqentry_exit_cond_resched)()
-#else
-#define irqentry_exit_cond_resched()	raw_irqentry_exit_cond_resched()
+#elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
+DECLARE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
If CONFIG_PREEMPT && CONFIG_PREEMPT_DYNAMIC and no "preempt=" parameter is
passed, nothing is overriden on boot. So you need to either have cond_resched
and might_resched initially disabled (STATIC_KEY_FALSE?) or call
sched_dynamic_update() from preempt_dynamic_init() also when CONFIG_PREEMPT=y.

Thanks.

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