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 50A1DC83F14 for ; Wed, 30 Aug 2023 20:08:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240383AbjH3UId (ORCPT ); Wed, 30 Aug 2023 16:08:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239850AbjH3UIV (ORCPT ); Wed, 30 Aug 2023 16:08:21 -0400 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 011FA6194 for ; Wed, 30 Aug 2023 12:56:37 -0700 (PDT) Received: by mail-pf1-x42b.google.com with SMTP id d2e1a72fcca58-68c576d35feso33222b3a.2 for ; Wed, 30 Aug 2023 12:56:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1693425329; x=1694030129; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=zizE0DsSac2//A2LFc2ofyEiL2FC+zRym04PXoZ7yO4=; b=Nwq28adhEI3SBMabCMw6Rjxy0VzdDmCltwttz8iQBNXDpx8+FDkMlwr3GbV6YCJOIP jOGjvNLlTE5xMebwE/6m+lfzr/ynKP5+UqwM89tS+mi4PeP1TJPclr6sKrATHK4+xt6C PBnUEEBWrybJlHZWUGQqa5CPvCxnUaclbRdqBBke5KxQzlfWLIkU3VEzGcgaMqe3FkFk MXnkrMTPcCx2mPuZWwrQvwn9BOkdV6dU+b87hndpvAjkFmOfZlNkdwXoRQyJftfoeSZc 9/udTqNceZsj8u4fGLtqbSn7MJ3TMXsQ4iISfYsQuQ4INp1HMF3Ou0WjK/iOim7/uSI1 B7sA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693425329; x=1694030129; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=zizE0DsSac2//A2LFc2ofyEiL2FC+zRym04PXoZ7yO4=; b=WiSM+f57lfk43/8r1GnPFwFIY6ozUT0gKpJt4eg8X/sogYyP48AITg8pJUDgvQjg1e Jl+rSbzfI4W3cTcTY+JwYN78FXt9NDsfWdpCFPOe1Sw/ngVec+blepOo0GF7ycj7PxXy c3ySIQ+RghJm18k/q6Vo0zy8K9CArnMOpzocHiYMeOU6I5EzAd7X/fxDPx9aXlskD85j 8B1BB43pBNG1VeVUu+IzlSlPU19Zcqbsi/bp9j6WcyC39ZxvOcu9vAHlTMb+RXRTR3Kk NDwC9MwJnRmeZxxO1qd6QtcAEzTem+BN+szfrstzWV2IZq9HqPfXGk4/JfohrwccPOhf tc+Q== X-Gm-Message-State: AOJu0YwYRfWyGIN/kAvgzwbzkSPYEmQs1gbGGVvhV4hyCXwby84Tnlkf 3tTvFLv84nghQJWhM1kw3Saup6PA4Wk= X-Google-Smtp-Source: AGHT+IGinyjODbtnyJ7zshYiV5beE4g63fxvnKTntkBt2OeDzh73rZ/XzOMb50Ri/geej4RKG63mfw== X-Received: by 2002:a05:6a20:8428:b0:134:30a8:9df5 with SMTP id c40-20020a056a20842800b0013430a89df5mr3953231pzd.43.1693425329068; Wed, 30 Aug 2023 12:55:29 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:9222]) by smtp.gmail.com with ESMTPSA id l2-20020a170902d34200b001bb9f104328sm11465888plk.146.2023.08.30.12.55.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Aug 2023 12:55:28 -0700 (PDT) Sender: Tejun Heo Date: Wed, 30 Aug 2023 09:55:27 -1000 From: Tejun Heo To: Mirsad Todorovac Cc: linux-kernel@vger.kernel.org, Lai Jiangshan Subject: Re: [PATCH v2 1/1] workqueue: fix data race with the pwq->stats[] increment Message-ID: References: <20230826145102.5962-1-mirsad.todorovac@alu.unizg.hr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Wed, Aug 30, 2023 at 09:48:53PM +0200, Mirsad Todorovac wrote: > These might just not have been triggered yet, but logically they seem suspicious for a data race. > I still have to verify if they are called from a locked context ... > > Of course, as the original developer, you will have a clearer picture. I have been led by KCSAN > to this particular detail. These are just stats and pwq's are already per-cpu (most of the time). If they trip kcsan and there's no easy way to work around like here, we should add a wrapper to inc the stat and annotate it so that kcsan ignores it. Thanks. -- tejun