From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753944AbaJ0TO2 (ORCPT ); Mon, 27 Oct 2014 15:14:28 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:52761 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753487AbaJ0TDk (ORCPT ); Mon, 27 Oct 2014 15:03:40 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Joe Thornber , Mikulas Patocka , Mike Snitzer , Kamal Mostafa Subject: [PATCH 3.13 074/105] dm bufio: update last_accessed when relinking a buffer Date: Mon, 27 Oct 2014 11:56:49 -0700 Message-Id: <1414436240-13879-75-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1414436240-13879-1-git-send-email-kamal@canonical.com> References: <1414436240-13879-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.10 -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: Kamal Mostafa --- 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 5056c45..bb8d23d 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; } /*---------------------------------------------------------------- -- 1.9.1