Commit d14ce74f authored Dec 02, 2020 by Frederic Weisbecker Committed by Thomas Gleixner Dec 02, 2020

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

parent d3759e71

kernel/softirq.c

+5 −9

Original line number	Diff line number	Diff line
		@@ -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);
		}

		/**

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