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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAD15C77B75 for ; Mon, 22 May 2023 11:55:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233549AbjEVLy7 (ORCPT ); Mon, 22 May 2023 07:54:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233109AbjEVLyv (ORCPT ); Mon, 22 May 2023 07:54:51 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 879CC9B for ; Mon, 22 May 2023 04:54:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684756444; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CmC7PRo1R7ZhJzowWuw/vFq8NrjJylR4K7gsroB369c=; b=fBOAjSzwz15pUukHZwZP9+9pm+Ju1apQLlCGtxl/PJf79F6jxWs0VbuviIUz+JVHd1RsmH TB4+ObX80AJ9LkWAiWTQr52sBt+GNKoF8WJ+57O9pHodCpzZhWJGIgjLQgEFI/bjNMi0Hi xQejeAkkM4tL+8J1z2fHhnc/UPmGChI= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-486-CKDAJogAOdeWtZlHmJVr3Q-1; Mon, 22 May 2023 07:54:03 -0400 X-MC-Unique: CKDAJogAOdeWtZlHmJVr3Q-1 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-3f50aa22cd2so35781025e9.1 for ; Mon, 22 May 2023 04:54:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684756442; x=1687348442; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=CmC7PRo1R7ZhJzowWuw/vFq8NrjJylR4K7gsroB369c=; b=bltPbxpN4HJhuq9+kRm6h6DRuyvaxMZEYA/DBjT/EwGnlSYcAM7Xd/H881f7OgkvRL t+0zhYKuZMtxItaqXq670tCfjSQBkh9AeKOl7GKa4MQd10kD0yLb9Nb5+i5pLE7wQJmk c/C38cACNXBGtA3lnyVImrH2INgjnCXev57a0+VutQmMAGmZkwYp3Zz3Ms5Yrcjf62bn 0riSKCVXTDX+Mpt5tl0TU2jhzOu/Zz/37qYz0c2RnbLXK+VbIlYashYQ4I4CXuAhZ6s6 plZRAUl1pdwEAP7C5xr/gcgUh7kkbb/2dLlr3FeaO1bZrM+fHDsV7834yvZBFSOFaYtK jAnA== X-Gm-Message-State: AC+VfDy8iv0HY6h1LKamawZkvPP5rriQ88CpbsgB6Wt7KBXOBdmDQWvK 9L5WHm4TRq38ANuWlPV6FIvzpH3QZrjLirMFCt9yD7o1FHd+fnQTbuH4qMZwcIpO4UtLyQERGEG uaklkSeHIAg3QM4xB2hGA9mdI X-Received: by 2002:a1c:7c19:0:b0:3f4:2374:3512 with SMTP id x25-20020a1c7c19000000b003f423743512mr6552770wmc.18.1684756442345; Mon, 22 May 2023 04:54:02 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ4EPlHuucVkDjDnagnkVzUlBwaBGqffjMZWuezvJJQlG5N32bC3QNWJX63pbfCrWjUb7Cmuzg== X-Received: by 2002:a1c:7c19:0:b0:3f4:2374:3512 with SMTP id x25-20020a1c7c19000000b003f423743512mr6552753wmc.18.1684756442017; Mon, 22 May 2023 04:54:02 -0700 (PDT) Received: from ?IPV6:2003:cb:c742:c800:d74f:aec6:f8ac:558? (p200300cbc742c800d74faec6f8ac0558.dip0.t-ipconnect.de. [2003:cb:c742:c800:d74f:aec6:f8ac:558]) by smtp.gmail.com with ESMTPSA id n6-20020a7bcbc6000000b003f42d8dd7ffsm8028624wmi.19.2023.05.22.04.54.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 22 May 2023 04:54:01 -0700 (PDT) Message-ID: <09cee859-6510-ed3c-67da-c1452a534460@redhat.com> Date: Mon, 22 May 2023 13:54:00 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH -V2 1/5] swap: Remove get/put_swap_device() in __swap_count() Content-Language: en-US To: Huang Ying , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hugh Dickins , Johannes Weiner , Matthew Wilcox , Michal Hocko , Minchan Kim , Tim Chen , Yang Shi , Yu Zhao References: <20230522070905.16773-1-ying.huang@intel.com> <20230522070905.16773-2-ying.huang@intel.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: <20230522070905.16773-2-ying.huang@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22.05.23 09:09, Huang Ying wrote: > __swap_count() is called in do_swap_page() only, which encloses the > call site with get/put_swap_device() already. > > Signed-off-by: "Huang, Ying" > Cc: David Hildenbrand > Cc: Hugh Dickins > Cc: Johannes Weiner > Cc: Matthew Wilcox > Cc: Michal Hocko > Cc: Minchan Kim > Cc: Tim Chen > Cc: Yang Shi > Cc: Yu Zhao > --- > mm/swapfile.c | 10 ++-------- > 1 file changed, 2 insertions(+), 8 deletions(-) > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 274bbf797480..8419cba9c192 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -1432,16 +1432,10 @@ void swapcache_free_entries(swp_entry_t *entries, int n) > > int __swap_count(swp_entry_t entry) > { > - struct swap_info_struct *si; > + struct swap_info_struct *si = swp_swap_info(entry); > pgoff_t offset = swp_offset(entry); > - int count = 0; > > - si = get_swap_device(entry); > - if (si) { > - count = swap_count(si->swap_map[offset]); > - put_swap_device(si); > - } > - return count; > + return swap_count(si->swap_map[offset]); > } > > /* That locking was added in eb085574a752 ("mm, swap: fix race between swapoff and some swap operations"). Before 2799e77529c ("swap: fix do_swap_page() race with swapoff") added the get_swap_device() to do_swap_page(). Reviewed-by: David Hildenbrand -- Thanks, David / dhildenb