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=unavailable 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 50613C5321D for ; Mon, 20 Apr 2020 01:03:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EBB692064A for ; Mon, 20 Apr 2020 01:03:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EBB692064A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5E7828E0005; Sun, 19 Apr 2020 21:03:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 598D38E0003; Sun, 19 Apr 2020 21:03:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4AE7C8E0005; Sun, 19 Apr 2020 21:03:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0078.hostedemail.com [216.40.44.78]) by kanga.kvack.org (Postfix) with ESMTP id 2F7E48E0003 for ; Sun, 19 Apr 2020 21:03:50 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id E3E96180ACF8F for ; Mon, 20 Apr 2020 01:03:49 +0000 (UTC) X-FDA: 76726436178.22.scale85_5b926001d2d16 X-HE-Tag: scale85_5b926001d2d16 X-Filterd-Recvd-Size: 2683 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Mon, 20 Apr 2020 01:03:49 +0000 (UTC) IronPort-SDR: xzmHWlZa3MDwt4nLxIY/m4///IQjrD7uXktQVbSJOWbUUJdbGhbFk9lEQ9XiWjhRt/1VRkbcy2 l7JMN1eJZDaA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Apr 2020 18:03:47 -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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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])