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 6F00CC7EE24 for ; Fri, 2 Jun 2023 12:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235450AbjFBMjZ (ORCPT ); Fri, 2 Jun 2023 08:39:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235581AbjFBMi6 (ORCPT ); Fri, 2 Jun 2023 08:38:58 -0400 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3BB421B4 for ; Fri, 2 Jun 2023 05:38:48 -0700 (PDT) Received: by mail-wr1-x429.google.com with SMTP id ffacd0b85a97d-3094910b150so2052875f8f.0 for ; Fri, 02 Jun 2023 05:38:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1685709526; x=1688301526; h=content-transfer-encoding:cc:to:subject:from:content-language :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=4OU+KWjof0+InLZd2Z+zpgcjkLN1kNtQWyAbuvbyUrk=; b=THMTmlN5uce2BLQVfhctAcE/ElUX8NGBjHT7ZwaEEpk7TrJXwy8U846OoMakn3sogC bhn9ipKsssaW5c8qvXobEpWZ51lv89/EojxzjAUwtEcwfz6O15ss3k676AmfEE6dDKIY 0ER3nmveAix1DnYC8oujXKVY1yYl66vs6rTOCw4OlFYBBpk11Li650O6j/JljHPi23kq +gunUqdF62aWlDOwOD9JA6JVPP+nqfKoiTkiL2ZG7zExPf0n74eN2O5JoDryVqvGx7yz TpYGm3Rm2k5/7vMBV3whTwPrzFMy/hmbF4foWat529V0ZqRhUBIdnyS1S0OGlMHLFZ/u EFeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685709526; x=1688301526; h=content-transfer-encoding:cc:to:subject:from:content-language :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=4OU+KWjof0+InLZd2Z+zpgcjkLN1kNtQWyAbuvbyUrk=; b=D55++v3PhdExQFfRL04hPjselqfroV6esbmj4zdXvIEKzuXbfXRR1ghQ89d4ZBkFPT s3czomGryC4EIewqc5mjqLTftVwd6POEJluFCtgE8Z6yXfpQFQVQ2J+kPXhHJRhy/cjW Zj/DwWeQdcYy/HVskxl7ZiTTraBvjKQgY7z55q9ut2MtA0cz2mR5lih1lDgQj16gaJDR 2iigWE87wI8Ke4D72v55mCUjaXm8Oy+rrrMWvZ1/nE1sfWmRsU0V2tvpCR3PTnPDIcXG 0pbzA6q0HVsLi2NBk4OltUGLz9cdjGkpK97pn2V2pbMQoiweywkIJkYVhZA15Vd5f6wz 1/Vg== X-Gm-Message-State: AC+VfDy7BuaiflylLCe2+ZtlKHCA8TzPuD989Ha/XRf8LiqGW/8iA0Ef Ya7jfyd1bWCRnorkB+5yDTY= X-Google-Smtp-Source: ACHHUZ4xZY9bylI1zvi3HVMwx5NHNkkt41dgybkWAqZVFxyRKX5FmKOcc3Ob9+9UCsSjSt42Sy71kA== X-Received: by 2002:a5d:49c4:0:b0:30a:dcba:2d81 with SMTP id t4-20020a5d49c4000000b0030adcba2d81mr3707936wrs.38.1685709526341; Fri, 02 Jun 2023 05:38:46 -0700 (PDT) Received: from [192.168.0.210] (cpc154979-craw9-2-0-cust193.16-3.cable.virginm.net. [80.193.200.194]) by smtp.googlemail.com with ESMTPSA id x11-20020a5d650b000000b00307972e46fasm1567347wru.107.2023.06.02.05.38.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 02 Jun 2023 05:38:45 -0700 (PDT) Message-ID: <1cbc8768-7a94-530d-f3ba-923038e6ef12@gmail.com> Date: Fri, 2 Jun 2023 13:38:44 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Content-Language: en-US From: "Colin King (gmail)" Subject: re: zswap: do not shrink if cgroup may not zswap To: Nhat Pham , Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , Johannes Weiner , Linux-MM Cc: "linux-kernel@vger.kernel.org" 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 Hi, static analysis with clang scan build has detected an issue in the following commit: commit 6804144bf1cfa3978ad98e625d8a1d2a4b80cbee Author: Nhat Pham Date: Tue May 30 15:24:40 2023 -0700 zswap: do not shrink if cgroup may not zswap The issue is as follows in function zswap_frontswap_store in mm/zswap.c: /* * XXX: zswap reclaim does not work with cgroups yet. Without a * cgroup-aware entry LRU, we will push out entries system-wide based on * local cgroup limits. */ objcg = get_obj_cgroup_from_page(page); if (objcg && !obj_cgroup_may_zswap(objcg)) goto reject; mm/zswap.c:1210:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] The goto reject path ends up returning ret, however, ret at this point has not been initialized, so a garbage return value is being returned by function zswap_frontswap_store Colin