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=-5.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 D82FEC4338F for ; Tue, 24 Aug 2021 23:27:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7507610F8 for ; Tue, 24 Aug 2021 23:27:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235622AbhHXX2E (ORCPT ); Tue, 24 Aug 2021 19:28:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233909AbhHXX2D (ORCPT ); Tue, 24 Aug 2021 19:28:03 -0400 Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 444FDC061757 for ; Tue, 24 Aug 2021 16:27:18 -0700 (PDT) Received: by mail-lf1-x135.google.com with SMTP id bq28so500745lfb.7 for ; Tue, 24 Aug 2021 16:27:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=RXUZYCE1kvj+2FOlsOE/g0PbS8+86ANN+fDn4eZ6uVM=; b=hvLw8Sq36xbrN7Xu0b22CBRdjw9qfSqhVGfamUDSw8+EAHAzAuzqg14044etAizESO SqPqC9ZzDCzRwtXPBdUcLo6IwLV/dLYx8DUXjq5BzPfIf3895qdVQfBkbI2rpW9sp7p7 gHkZzbL3ly5UuRCofrW2M4kiob6sjdVSqvhVE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=RXUZYCE1kvj+2FOlsOE/g0PbS8+86ANN+fDn4eZ6uVM=; b=rgnf72M51+4Ig9PxvGVzTQWSDZQ2XKdVeUl6NdlvxkJBX+FZEwpPHmYSOCpo4nfwyj nEG76KFTM5VW4h5pc0RK0/++U7D9CrGNa4MPFO3PA2FPt8uZkECBmMHOqDBgPoV7YVgk 9xNWgjFIS/xAc9xo2Rn0UsqnvzX+yef1WwBgGvuqRXI4QzYYFMz977HmtapAgEsibbEW Z/vkf6xyOhHOAYf5xGivXxHcJL9FT30Fl5n9ndoEu3yiwJ21k90GavfqPGzEPHyn/rHf 2EEDn8XkQuWNy+ijLMZKschzkHrhyFWj/elOtMMNE2ZyZJXTnBxWJM2814HNRqiWMQVK M4IQ== X-Gm-Message-State: AOAM530SOQmSoWBjNS4df0oSbmnaMbej1UYNDCvNYbvOwB/jXhxOXLyO b3Ps49bMPOe/hQDj0Tx8ui8y2AV30zY3Pr9C X-Google-Smtp-Source: ABdhPJxddyaZcBDFtccix+7ygxFwb4b6PnHMLrxdwSdoMK4xlRyLOYS4GFrrqWhPw4lUCPrnd3FDqw== X-Received: by 2002:a05:6512:1042:: with SMTP id c2mr30800099lfb.283.1629847636483; Tue, 24 Aug 2021 16:27:16 -0700 (PDT) Received: from mail-lj1-f178.google.com (mail-lj1-f178.google.com. [209.85.208.178]) by smtp.gmail.com with ESMTPSA id t70sm1882217lff.91.2021.08.24.16.27.15 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 24 Aug 2021 16:27:15 -0700 (PDT) Received: by mail-lj1-f178.google.com with SMTP id y6so40444700lje.2 for ; Tue, 24 Aug 2021 16:27:15 -0700 (PDT) X-Received: by 2002:a2e:81c2:: with SMTP id s2mr32547167ljg.48.1629847635304; Tue, 24 Aug 2021 16:27:15 -0700 (PDT) MIME-Version: 1.0 References: <20210824031648.GA2725@codemonkey.org.uk> <20210824151943.GA386@codemonkey.org.uk> <20210824213342.GA1708@codemonkey.org.uk> In-Reply-To: <20210824213342.GA1708@codemonkey.org.uk> From: Linus Torvalds Date: Tue, 24 Aug 2021 16:26:59 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: 5.14-rc breaks iotop swap io monitoring. To: Dave Jones , Linus Torvalds , Peter Zijlstra , Linux Kernel , Johannes Weiner Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 24, 2021 at 2:41 PM Dave Jones wrote: > > On Tue, Aug 24, 2021 at 09:34:02AM -0700, Linus Torvalds wrote: > > > > What happens if you boot with the 'delayacct' kernel parameter. > > > > Even if you enable it at run-time, processes that have been started > > before it was enabled won't actually have the 'tsk->delays' > > allocation. So I'm not sure how effective the run-time thing is. > > Yeah that boot option does make iotop work again. Ok, so it's that delay allocation thing is it. I'm inclined to let it be and see if somebody else notices, and how big of a deal it is. The 'delayacct' kernel command line is an acceptable workaround if this is something only a few people will even notice or care about. I wonder how much people care about some statistics and iotop these days. I also assume the swap stats still show up in "vmstat" etc, and that it's just that iotop ended up using fancier interfaces? Or do I assume wrongly? Linus