From 4bb6e96ab808f88d746343637f0cc2243b527da5 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 27 Jun 2018 23:26:01 -0700 Subject: [PATCH] lib/percpu_ida.c: don't do alloc from per-CPU list if there is none In commit 804209d8a009 ("lib/percpu_ida.c: use _irqsave() instead of local_irq_save() + spin_lock") I inlined alloc_local_tag() and mixed up the >= check from percpu_ida_alloc() with the one in alloc_local_tag(). Don't alloc from per-CPU freelist if ->nr_free is zero. Link: http://lkml.kernel.org/r/20180613075830.c3zeva52fuj6fxxv@linutronix.de Fixes: 804209d8a009 ("lib/percpu_ida.c: use _irqsave() instead of local_irq_save() + spin_lock") Signed-off-by: Sebastian Andrzej Siewior Reported-by: David Disseldorp Tested-by: David Disseldorp Cc: Thomas Gleixner Cc: Nicholas Bellinger Cc: Shaohua Li Cc: Kent Overstreet Cc: Matthew Wilcox Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/percpu_ida.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c index 9bbd9c5d375a..beb14839b41a 100644 --- a/lib/percpu_ida.c +++ b/lib/percpu_ida.c @@ -141,7 +141,7 @@ int percpu_ida_alloc(struct percpu_ida *pool, int state) spin_lock_irqsave(&tags->lock, flags); /* Fastpath */ - if (likely(tags->nr_free >= 0)) { + if (likely(tags->nr_free)) { tag = tags->freelist[--tags->nr_free]; spin_unlock_irqrestore(&tags->lock, flags); return tag; -- 2.20.1