From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Christoph Hellwig <hch@infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH] irq_poll: Use raise_softirq_irqoff() in cpu_dead notifier
Date: Thu, 30 Sep 2021 12:37:54 +0200 [thread overview]
Message-ID: <20210930103754.2128949-1-bigeasy@linutronix.de> (raw)
__raise_softirq_irqoff() adds a bit to the pending sofirq mask and this
is it. The softirq won't be handled in a deterministic way but randomly
when an interrupt fires and handles softirq in its irq_exit() routine or
if something randomly checks and handles pending softirqs in the call
chain before the CPU goes idle.
Add a local_bh_disable/enable() around the IRQ-off section which will
handle pending softirqs.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
lib/irq_poll.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/lib/irq_poll.c b/lib/irq_poll.c
index 2f17b488d58e1..2b9f797642f60 100644
--- a/lib/irq_poll.c
+++ b/lib/irq_poll.c
@@ -191,11 +191,13 @@ static int irq_poll_cpu_dead(unsigned int cpu)
* If a CPU goes away, splice its entries to the current CPU
* and trigger a run of the softirq
*/
+ local_bh_disable();
local_irq_disable();
list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
this_cpu_ptr(&blk_cpu_iopoll));
__raise_softirq_irqoff(IRQ_POLL_SOFTIRQ);
local_irq_enable();
+ local_bh_enable();
return 0;
}
--
2.33.0
next reply other threads:[~2021-09-30 10:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-30 10:37 Sebastian Andrzej Siewior [this message]
2021-09-30 10:56 ` [RFC] Is lib/irq_poll still considered useful? Sebastian Andrzej Siewior
2021-10-01 4:24 ` Christoph Hellwig
2021-10-01 6:41 ` Sebastian Andrzej Siewior
2021-10-18 7:45 ` [PATCH] irq_poll: Use raise_softirq_irqoff() in cpu_dead notifier Sebastian Andrzej Siewior
2021-10-18 10:53 ` Christoph Hellwig
2021-10-18 11:49 ` Sebastian Andrzej Siewior
-- strict thread matches above, loose matches on Subject: below --
2020-04-02 19:50 Sebastian Andrzej Siewior
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