Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751692AbdITFnj (ORCPT ); Wed, 20 Sep 2017 01:43:39 -0400 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:41757 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751547AbdITFne (ORCPT ); Wed, 20 Sep 2017 01:43:34 -0400 X-Original-SENDERIP: 156.147.1.151 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.220.163 X-Original-MAILFROM: minchan@kernel.org From: Minchan Kim To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team , Christoph Hellwig , Minchan Kim , Hugh Dickins Subject: [PATCH v2 3/4] mm:swap: introduce SWP_SYNCHRONOUS_IO Date: Wed, 20 Sep 2017 14:43:24 +0900 Message-Id: <1505886205-9671-4-git-send-email-minchan@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1505886205-9671-1-git-send-email-minchan@kernel.org> References: <1505886205-9671-1-git-send-email-minchan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1555 Lines: 43 If rw-page based fast storage is used for swap devices, we need to detect it to enhance swap IO operations. This patch is preparation for optimizing of swap-in operation with next patch. Cc: Hugh Dickins Signed-off-by: Minchan Kim --- include/linux/swap.h | 3 ++- mm/swapfile.c | 3 +++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 8a807292037f..fbb33919d1c6 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -170,8 +170,9 @@ enum { SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */ SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */ SWP_STABLE_WRITES = (1 << 10), /* no overwrite PG_writeback pages */ + SWP_SYNCHRONOUS_IO = (1 << 11), /* synchronous IO is efficient */ /* add others here before... */ - SWP_SCANNING = (1 << 11), /* refcount in scan_swap_map */ + SWP_SCANNING = (1 << 12), /* refcount in scan_swap_map */ }; #define SWAP_CLUSTER_MAX 32UL diff --git a/mm/swapfile.c b/mm/swapfile.c index bf91dc9e7a79..1305591cde4d 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3168,6 +3168,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (bdi_cap_stable_pages_required(inode_to_bdi(inode))) p->flags |= SWP_STABLE_WRITES; + if (bdi_cap_synchronous_io(inode_to_bdi(inode))) + p->flags |= SWP_SYNCHRONOUS_IO; + if (p->bdev && blk_queue_nonrot(bdev_get_queue(p->bdev))) { int cpu; unsigned long ci, nr_cluster; -- 2.7.4