From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966018AbaKLBvJ (ORCPT ); Tue, 11 Nov 2014 20:51:09 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:32788 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965975AbaKLBu5 (ORCPT ); Tue, 11 Nov 2014 20:50:57 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joe Thornber , Mikulas Patocka , Mike Snitzer Subject: [PATCH 3.10 036/123] dm bufio: update last_accessed when relinking a buffer Date: Wed, 12 Nov 2014 10:16:42 +0900 Message-Id: <20141112011720.663094204@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141112011718.985171261@linuxfoundation.org> References: <20141112011718.985171261@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable 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 Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-bufio.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -462,6 +462,7 @@ static void __relink_lru(struct dm_buffe c->n_buffers[dirty]++; b->list_mode = dirty; list_move(&b->lru_list, &c->lru[dirty]); + b->last_accessed = jiffies; } /*----------------------------------------------------------------