From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21470ECDE5F for ; Thu, 19 Jul 2018 08:48:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB28E2084C for ; Thu, 19 Jul 2018 08:48:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB28E2084C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731053AbeGSJbA (ORCPT ); Thu, 19 Jul 2018 05:31:00 -0400 Received: from mga04.intel.com ([192.55.52.120]:10706 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725985AbeGSJa7 (ORCPT ); Thu, 19 Jul 2018 05:30:59 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Jul 2018 01:48:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,374,1526367600"; d="scan'208";a="76038263" Received: from yhuang6-ux31a.sh.intel.com ([10.239.195.246]) by orsmga002.jf.intel.com with ESMTP; 19 Jul 2018 01:48:50 -0700 From: Huang Ying To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , Michal Hocko , Johannes Weiner , Shaohua Li , Hugh Dickins , Minchan Kim , Rik van Riel , Dan Williams , Dave Hansen , Daniel Jordan Subject: [PATCH v3 1/8] swap: Add comments to lock_cluster_or_swap_info() Date: Thu, 19 Jul 2018 16:48:35 +0800 Message-Id: <20180719084842.11385-2-ying.huang@intel.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20180719084842.11385-1-ying.huang@intel.com> References: <20180719084842.11385-1-ying.huang@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To improve the code readability. Signed-off-by: "Huang, Ying" Suggested-by: Dave Hansen Reviewed-by: Daniel Jordan Cc: Michal Hocko Cc: Johannes Weiner Cc: Shaohua Li Cc: Hugh Dickins Cc: Minchan Kim Cc: Rik van Riel Cc: Dan Williams --- mm/swapfile.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/swapfile.c b/mm/swapfile.c index d8fddfb000ec..29da44411734 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -297,13 +297,19 @@ static inline void unlock_cluster(struct swap_cluster_info *ci) spin_unlock(&ci->lock); } +/* + * Determine the locking method in use for this device. Return + * swap_cluster_info if SSD-style cluster-based locking is in place. + */ static inline struct swap_cluster_info *lock_cluster_or_swap_info( struct swap_info_struct *si, unsigned long offset) { struct swap_cluster_info *ci; + /* Try to use fine-grained SSD-style locking if available: */ ci = lock_cluster(si, offset); + /* Otherwise, fall back to traditional, coarse locking: */ if (!ci) spin_lock(&si->lock); -- 2.16.4