From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7EBBA200A0 for ; Wed, 12 Jul 2023 09:58:06 +0000 (UTC) Received: from mail-yw1-f176.google.com (mail-yw1-f176.google.com [209.85.128.176]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B0271720; Wed, 12 Jul 2023 02:58:05 -0700 (PDT) Received: by mail-yw1-f176.google.com with SMTP id 00721157ae682-5768a7e3adbso8595087b3.0; Wed, 12 Jul 2023 02:58:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689155884; x=1691747884; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Y6MzudJP2Fu/sGdEnelPPluUqTi475Db7xeaDmuW9Sk=; b=LJrwQd7/GT/f6oIF/VO5++yTV31g4WJbSQ1fWlc/6aaAe0vQvJYr4kByUnVfNzoT7X 3q3FGJZT/6Z6RHfymi63tAJPT1EY2iwRa75CXHjS3Ot25+fRu84WDKLN9xUi8pxJQluj PwGyOtMkZiK8HKdqp2iAgC0FDJFT+heoiVo5a8pdlw7A+EuipACA1m7X08NZYQuLg/OD 4BH/kujvK/Db+8rFjpsFKMfyxPvqea1avTy6JQUB0jahhM9Itqqy49SgaLfGIPhGEnbL ljW/5yIUDSlUn4axOB9G4IApIlfDzHpZdHk/JMhE1rmohX36QxlmsHnsHGtr/7g1jdHD Kl4w== X-Gm-Message-State: ABy/qLY/EwIOYS6AZrz2ivULfQAnXCA21K/X7hfKfuI+kiyLNdahXYQ4 UHdcDF7kMwh4RmGN6+ZFK/Up2wQ6pmTPxA== X-Google-Smtp-Source: APBJJlGYudo9gVR+Cou01gtan/TCm1WXI5ja4PeIWua5VW5I2pAP/ypMPtV4ncbiIL0wMtb9qlUwGw== X-Received: by 2002:a0d:d616:0:b0:573:284d:6476 with SMTP id y22-20020a0dd616000000b00573284d6476mr1711934ywd.1.1689155884332; Wed, 12 Jul 2023 02:58:04 -0700 (PDT) Received: from mail-yb1-f178.google.com (mail-yb1-f178.google.com. [209.85.219.178]) by smtp.gmail.com with ESMTPSA id f67-20020a816a46000000b0057a93844c15sm1059234ywc.127.2023.07.12.02.58.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 12 Jul 2023 02:58:03 -0700 (PDT) Received: by mail-yb1-f178.google.com with SMTP id 3f1490d57ef6-ca9804dc6e4so198576276.0; Wed, 12 Jul 2023 02:58:03 -0700 (PDT) X-Received: by 2002:a25:ae5d:0:b0:bd6:a97e:3597 with SMTP id g29-20020a25ae5d000000b00bd6a97e3597mr1632945ybe.30.1689155883328; Wed, 12 Jul 2023 02:58:03 -0700 (PDT) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20230511181931.869812-1-tj@kernel.org> <20230511181931.869812-7-tj@kernel.org> In-Reply-To: From: Geert Uytterhoeven Date: Wed, 12 Jul 2023 11:57:49 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Consider switching to WQ_UNBOUND messages (was: Re: [PATCH v2 6/7] workqueue: Report work funcs that trigger automatic CPU_INTENSIVE mechanism) To: Tejun Heo Cc: Lai Jiangshan , "torvalds@linux-foundation.org" , Peter Zijlstra , Linux Kernel Mailing List , kernel-team@meta.com, Linux PM list , DRI Development , linux-rtc@vger.kernel.org, linux-riscv , netdev , Linux Fbdev development list , Linux MMC List , "open list:LIBATA SUBSYSTEM (Serial and Parallel ATA drivers)" , Linux-Renesas Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Hi Tejun, On Wed, Jul 12, 2023 at 2:30=E2=80=AFAM Tejun Heo wrote: > On Tue, Jul 11, 2023 at 11:39:17AM -1000, Tejun Heo wrote: > > On Tue, Jul 11, 2023 at 04:06:22PM +0200, Geert Uytterhoeven wrote: > > > On Tue, Jul 11, 2023 at 3:55=E2=80=AFPM Geert Uytterhoeven wrote: > ... > > > workqueue: neigh_managed_work hogged CPU for >10000us 4 times, > > > consider switching to WQ_UNBOUND > > > > I wonder whether the right thing to do here is somehow scaling the thre= shold > > according to the relative processing power. It's difficult to come up w= ith a > > threshold which works well across the latest & fastest and really tiny = CPUs. > > I'll think about it some more but if you have some ideas, please feel f= ree > > to suggest. > > Geert, do you mind posting the full kernel logs for the affected machines= ? https://drive.google.com/file/d/1toDs7ugZJ2eXatpdvySY4yxSsNam9xAC is an archive with boot and s2ram logs. Note that my kernels do contain local debug code, and may be noisy. Gr{oetje,eeting}s, Geert --=20 Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k= .org In personal conversations with technical people, I call myself a hacker. Bu= t when I'm talking to journalists I just say "programmer" or something like t= hat. -- Linus Torvalds