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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 0E8B2C38A29 for ; Mon, 20 Apr 2020 01:03:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE3002064A for ; Mon, 20 Apr 2020 01:03:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726025AbgDTBDq (ORCPT ); Sun, 19 Apr 2020 21:03:46 -0400 Received: from mga04.intel.com ([192.55.52.120]:2723 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725949AbgDTBDq (ORCPT ); Sun, 19 Apr 2020 21:03:46 -0400 IronPort-SDR: SV1sq4NIbHFCv/Bdbxvosxc/BMQNqjVbA89U0BUUwCqaffdmwg2K0RM+mRkExAHe9IQDoI6cXA TCjEGTS9jiMA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Apr 2020 18:03:46 -0700 IronPort-SDR: fW3Emu5AXRqLLewgTQcdcurUevbhcclKe+GY2wxiKpczEMkA9ZfkmyNklZVPDbuE/71bbd3jQi 2Ob828pgvmlg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,405,1580803200"; d="scan'208";a="300141109" Received: from yhuang-dev.sh.intel.com (HELO yhuang-dev) ([10.239.159.23]) by FMSMGA003.fm.intel.com with ESMTP; 19 Apr 2020 18:03:43 -0700 From: "Huang\, Ying" To: Wei Yang Cc: , , , Subject: Re: [PATCH 3/4] mm/swapfile.c: compare tmp and max after trying to iterate on swap_map References: <20200419013921.14390-1-richard.weiyang@gmail.com> <20200419013921.14390-3-richard.weiyang@gmail.com> Date: Mon, 20 Apr 2020 09:03:43 +0800 In-Reply-To: <20200419013921.14390-3-richard.weiyang@gmail.com> (Wei Yang's message of "Sun, 19 Apr 2020 01:39:20 +0000") Message-ID: <87ftczt1cg.fsf@yhuang-dev.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Wei Yang writes: > There are two duplicate code to handle the case when there is no > available swap entry. Just let the code go through and do the check at > second place. > > No functional change is expected. > > Signed-off-by: Wei Yang > --- > mm/swapfile.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 3aae700f9931..07b0bc095411 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -629,10 +629,6 @@ static bool scan_swap_map_try_ssd_cluster(struct swap_info_struct *si, > tmp = cluster->next; > max = min_t(unsigned long, si->max, > (cluster_next(&cluster->index) + 1) * SWAPFILE_CLUSTER); > - if (tmp >= max) { > - cluster_set_null(&cluster->index); > - goto new_cluster; > - } The code is to avoid to acquire the cluster lock unnecessarily. So I think we should keep this. Best Regards, Huang, Ying > ci = lock_cluster(si, tmp); > while (tmp < max) { > if (!si->swap_map[tmp])