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authorFrederic Weisbecker <frederic@kernel.org>2020-12-02 12:57:32 +0100
committerThomas Gleixner <tglx@linutronix.de>2020-12-02 20:20:05 +0100
commitd14ce74f1fb376ccbbc0b05ded477ada51253729 (patch)
tree4458ca24e001e08e17815d169d1266690c02cd2a
parentd3759e7184f8f6187e62f8c4e7dcb1f6c47c075a (diff)
downloadlinux-d14ce74f1fb376ccbbc0b05ded477ada51253729.tar.gz
irq: Call tick_irq_enter() inside HARDIRQ_OFFSET
Now that account_hardirq_enter() is called after HARDIRQ_OFFSET has
been incremented, there is nothing left that prevents us from also
moving tick_irq_enter() after HARDIRQ_OFFSET is incremented.

The desired outcome is to remove the nasty hack that prevents softirqs
from being raised through ksoftirqd instead of the hardirq bottom half.
Also tick_irq_enter() then becomes appropriately covered by lockdep.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-6-frederic@kernel.org

-rw-r--r--kernel/softirq.c14
1 files changed, 5 insertions, 9 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c
index b8f42b3ba8ca..d5bfd5e661fc 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -377,16 +377,12 @@ restart:
  */
 void irq_enter_rcu(void)
 {
-	if (is_idle_task(current) && !in_interrupt()) {
-		/*
-		 * Prevent raise_softirq from needlessly waking up ksoftirqd
-		 * here, as softirq will be serviced on return from interrupt.
-		 */
-		local_bh_disable();
+	__irq_enter_raw();
+
+	if (is_idle_task(current) && (irq_count() == HARDIRQ_OFFSET))
 		tick_irq_enter();
-		_local_bh_enable();
-	}
-	__irq_enter();
+
+	account_hardirq_enter(current);
 }
 
 /**