Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756580AbaKRPGv (ORCPT ); Tue, 18 Nov 2014 10:06:51 -0500 Received: from cantor2.suse.de ([195.135.220.15]:57203 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932068AbaKROJj (ORCPT ); Tue, 18 Nov 2014 09:09:39 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Joe Thornber , Mikulas Patocka , Mike Snitzer , Jiri Slaby Subject: [PATCH 3.12 086/206] dm bufio: update last_accessed when relinking a buffer Date: Tue, 18 Nov 2014 15:07:21 +0100 Message-Id: <15188b0745439aa1f686e6eb55cacabbe2ea0244.1416319692.git.jslaby@suse.cz> X-Mailer: git-send-email 2.1.3 In-Reply-To: <28f04bcc068a44c5641c727883947960fb8dcbd5.1416319692.git.jslaby@suse.cz> References: <28f04bcc068a44c5641c727883947960fb8dcbd5.1416319692.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joe Thornber 3.12-stable 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 Signed-off-by: Jiri Slaby --- 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 5056c45be97f..bb8d23d55c4a 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -463,6 +463,7 @@ static void __relink_lru(struct dm_buffer *b, int dirty) c->n_buffers[dirty]++; b->list_mode = dirty; list_move(&b->lru_list, &c->lru[dirty]); + b->last_accessed = jiffies; } /*---------------------------------------------------------------- -- 2.1.3 -- 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/