Commit 060288a7 authored Aug 21, 2018 by Anna-Maria Gleixner Committed by Linus Torvalds Aug 22, 2018

bdi: use irqsave variant of refcount_dec_and_lock()

The irqsave variant of refcount_dec_and_lock handles irqsave/restore when
taking/releasing the spin lock.  With this variant the call of
local_irq_save/restore is no longer required.

[bigeasy@linutronix.de: s@atomic_dec_and_lock@refcount_dec_and_lock@g]
Link: http://lkml.kernel.org/r/20180703200141.28415-5-bigeasy@linutronix.de


Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e58dd0de

mm/backing-dev.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -473,11 +473,8 @@ void wb_congested_put(struct bdi_writeback_congested *congested)
		{
		unsigned long flags;

		local_irq_save(flags);
		if (!refcount_dec_and_lock(&congested->refcnt, &cgwb_lock)) {
		local_irq_restore(flags);
		if (!refcount_dec_and_lock_irqsave(&congested->refcnt, &cgwb_lock, &flags))
		return;
		}

		/* bdi might already have been destroyed leaving @congested unlinked */
		if (congested->__bdi) {

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