From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 4C5356B0261 for ; Wed, 20 Sep 2017 01:43:35 -0400 (EDT) Received: by mail-pg0-f70.google.com with SMTP id i130so3539659pgc.5 for ; Tue, 19 Sep 2017 22:43:35 -0700 (PDT) Received: from lgeamrelo11.lge.com (LGEAMRELO11.lge.com. [156.147.23.51]) by mx.google.com with ESMTP id h6si772220pll.259.2017.09.19.22.43.33 for ; Tue, 19 Sep 2017 22:43:34 -0700 (PDT) From: Minchan Kim 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> In-Reply-To: <1505886205-9671-1-git-send-email-minchan@kernel.org> References: <1505886205-9671-1-git-send-email-minchan@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team , Christoph Hellwig , Minchan Kim , Hugh Dickins 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org