From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933887AbbA1ERM (ORCPT ); Tue, 27 Jan 2015 23:17:12 -0500 Received: from mail.kernel.org ([198.145.29.136]:37983 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933857AbbA1ERH (ORCPT ); Tue, 27 Jan 2015 23:17:07 -0500 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Joe Thornber , Mikulas Patocka , Mike Snitzer , Zefan Li Subject: [PATCH 3.4 040/177] dm bufio: update last_accessed when relinking a buffer Date: Wed, 28 Jan 2015 12:07:26 +0800 Message-Id: <1422418236-12852-79-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1422418050-12581-1-git-send-email-lizf@kernel.org> References: <1422418050-12581-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joe Thornber 3.4.106-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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 [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li --- drivers/md/dm-bufio.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 6f99500..5abc8d6 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -467,6 +467,7 @@ static void __relink_lru(struct dm_buffer *b, int dirty) b->list_mode = dirty; list_del(&b->lru_list); list_add(&b->lru_list, &c->lru[dirty]); + b->last_accessed = jiffies; } /*---------------------------------------------------------------- -- 1.9.1