Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760329AbaLLGWq (ORCPT ); Fri, 12 Dec 2014 01:22:46 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51808 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759466AbaLLGRN (ORCPT ); Fri, 12 Dec 2014 01:17:13 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Mike Snitzer" , "Mikulas Patocka" , "Joe Thornber" Date: Fri, 12 Dec 2014 06:14:25 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 044/164] dm bufio: update last_accessed when relinking a buffer In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:c97:8151:cc89:c28d X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.65-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Joe Thornber commit eb76faf53b1ff7a77ce3f78cc98ad392ac70c2a0 upstream. The 'last_accessed' member of the dm_buffer structure was only set when the the buffer was created. This led to each buffer being discarded after dm_bufio_max_age time even if it was used recently. In practice this resulted in all thinp metadata being evicted soon after being read -- this is particularly problematic for metadata intensive workloads like multithreaded small random IO. 'last_accessed' is now updated each time the buffer is moved to the head of the LRU list, so the buffer is now properly discarded if it was not used in dm_bufio_max_age time. Signed-off-by: Joe Thornber Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- drivers/md/dm-bufio.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -468,6 +468,7 @@ static void __relink_lru(struct dm_buffe b->list_mode = dirty; list_del(&b->lru_list); list_add(&b->lru_list, &c->lru[dirty]); + b->last_accessed = jiffies; } /*---------------------------------------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/