Commit a91befde authored by wuchi's avatar wuchi Committed by Andrew Morton
Browse files

lib/flex_proportions.c: remove local_irq_ops in fprop_new_period() 

commit e78d4833> "lib: Fix possible deadlock in flexible proportion
code" adds the local_irq_ops because percpu_counter_{sum |add} ops'lock
can cause deadlock by interrupts.  Now percpu_counter _{sum|add} ops use
raw_spin_(un)lock_irq*, so revert the commit and resolve the conflict.

Link: https://lkml.kernel.org/r/20220604131502.5190-1-wuchi.zero@gmail.com


Signed-off-by: default avatarwuchi <wuchi.zero@gmail.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 0cc011c5

lib/flex_proportions.c

+2 −8
Original line number Diff line number Diff line
@@ -63,18 +63,13 @@ void fprop_global_destroy(struct fprop_global *p) 
 */

bool fprop_new_period(struct fprop_global *p, int periods)

{

	s64 events;

	unsigned long flags;

	s64 events = percpu_counter_sum(&p->events);



	local_irq_save(flags);

	events = percpu_counter_sum(&p->events);

	/*

	 * Don't do anything if there are no events.

	 */

	if (events <= 1) {

		local_irq_restore(flags);

	if (events <= 1)

		return false;

	}

	write_seqcount_begin(&p->sequence);

	if (periods < 64)

		events -= events >> periods;
@@ -82,7 +77,6 @@ bool fprop_new_period(struct fprop_global *p, int periods) 
	percpu_counter_add(&p->events, -events);

	p->period += periods;

	write_seqcount_end(&p->sequence);

	local_irq_restore(flags);



	return true;

}