From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To: akpm@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org,
Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Subject: [PATCH] mm/mremap_pages: Save a few cycles in 'get_dev_pagemap()'
Date: Wed, 3 Nov 2021 22:35:34 +0100 [thread overview]
Message-ID: <b4a47154877853cc64be3a35dcfd594d40cc2bce.1635975283.git.christophe.jaillet@wanadoo.fr> (raw)
Use 'percpu_ref_tryget_live_rcu()' instead of 'percpu_ref_tryget_live()' to
save a few cycles when it is known that the rcu lock is already
taken/released.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
mm/memremap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/memremap.c b/mm/memremap.c
index 84de22c14567..012e8d23d365 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -506,7 +506,7 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
/* fall back to slow path lookup */
rcu_read_lock();
pgmap = xa_load(&pgmap_array, PHYS_PFN(phys));
- if (pgmap && !percpu_ref_tryget_live(pgmap->ref))
+ if (pgmap && !percpu_ref_tryget_live_rcu(pgmap->ref))
pgmap = NULL;
rcu_read_unlock();
--
2.30.2
next reply other threads:[~2021-11-03 21:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-03 21:35 Christophe JAILLET [this message]
2021-11-03 21:41 ` Matthew Wilcox
2021-11-03 21:54 ` Christophe JAILLET
2021-11-03 22:01 ` Matthew Wilcox
2022-08-12 4:58 ` Christophe JAILLET
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