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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 6334CC32771 for ; Sat, 18 Jan 2020 19:20:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 355772468B for ; Sat, 18 Jan 2020 19:20:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="giklA9pm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727104AbgARTUX (ORCPT ); Sat, 18 Jan 2020 14:20:23 -0500 Received: from mail-lf1-f44.google.com ([209.85.167.44]:45934 "EHLO mail-lf1-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726658AbgARTUX (ORCPT ); Sat, 18 Jan 2020 14:20:23 -0500 Received: by mail-lf1-f44.google.com with SMTP id 203so20875114lfa.12 for ; Sat, 18 Jan 2020 11:20:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:from:subject:autocrypt:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=UZm6Tag438/RN9lcYCGvGRdSS8+GAe42odyAEtSG3Pc=; b=giklA9pmt6me4dBgboCreAAn6rrMRyWFWx4AWFRfZGx3+5ZQGuv8nxY58vM0xDtFqt K6ZXy6/0EwjZIE0ntILcBR4B6nglg/koy/4stikTC+6lv8btlXdlgOTs/LgtLYR4vu9T ElTtP2FN0ze83j9QdtVgvb+MOvd5ka8eXa18jt0l0omJcHj3IifvVe9C/m1xA0WXokWV O0bULEKD9QSRlx+PwBTN5FQLXee5Je6Sskd6qDEHv6yUQpRO7u1u3NbTzWur9zs3iwv1 Sbruod8Elealyb2oyd7etzZj17Xr7+FCGGhdnPYXv7lpLB78Gh3MbZeI4MxnmU/lb9eC tR3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:from:subject:autocrypt:message-id:date :user-agent:mime-version:content-language:content-transfer-encoding; bh=UZm6Tag438/RN9lcYCGvGRdSS8+GAe42odyAEtSG3Pc=; b=maMSavR+oc2tkzsclWz16vi0dTEoX8Rp/1bKun0hIFkFNFOzbyd2pcZPuTKyZXifwf Ln7OhxagSsNw6zgjPKDXH6oSr2lSaTaUFJyTc/bKOSDgayc+7yxvPn2ruwiRBmClNTY1 SJ3ePR/BMwVzTLd5R2cI3AHLTZSsbdagjQLxl2oALMBS7NdgLPYGK1sfhLm8msOe7Lfe xkiExdTqD1LhG6vxH6UdKHyJi5M18jrkv+Et7Z60FXq5nXZSywoe3n2jiAx0hBQRn3ay 8ZKJi2A0QardwjJQcova1AbZj2noi5lSQkCunviqJYT2CzKVzSaqpERY6Lf0fMPypQ4B rd1w== X-Gm-Message-State: APjAAAUwgDmxfSn+26HPsuqXapjElJTCBLts6MEg9tz5o6Lav8PTY/QV zYapmUFcormVjxko2TaFzvSb61XP X-Google-Smtp-Source: APXvYqxsvCPZFFJ94Q+cC8EqaBPYfp2z+nAxRkOeSdXvAzeY6x+1ob+mCnLM/DvLwWoNBAdp1Bit1A== X-Received: by 2002:ac2:531b:: with SMTP id c27mr8847490lfh.91.1579375220510; Sat, 18 Jan 2020 11:20:20 -0800 (PST) Received: from ?IPv6:2a00:1370:812d:af15:a51e:b905:dd2b:45cf? ([2a00:1370:812d:af15:a51e:b905:dd2b:45cf]) by smtp.gmail.com with ESMTPSA id n11sm14244109ljg.15.2020.01.18.11.20.19 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 18 Jan 2020 11:20:19 -0800 (PST) To: linux-kernel@vger.kernel.org From: Andrei Borzenkov Subject: Stuttering (mouse, keyboard input, video) in 5.3/5.4 when swap is being used. Autocrypt: addr=arvidjaar@gmail.com; prefer-encrypt=mutual; keydata= xsDiBDxiRwwRBAC3CN9wdwpVEqUGmSoqF8tWVIT4P/bLCSZLkinSZ2drsblKpdG7x+guxwts +LgI8qjf/q5Lah1TwOqzDvjHYJ1wbBauxZ03nDzSLUhD4Ms1IsqlIwyTLumQs4vcQdvLxjFs G70aDglgUSBogtaIEsiYZXl4X0j3L9fVstuz4/wXtwCg1cN/yv/eBC0tkcM1nsJXQrC5Ay8D /1aA5qPticLBpmEBxqkf0EMHuzyrFlqVw1tUjZ+Ep2LMlem8malPvfdZKEZ71W1a/XbRn8FE SOp0tUa5GwdoDXgEp1CJUn+WLurR0KPDf01E4j/PHHAoABgrqcOTcIVoNpv2gNiBySVsNGzF XTeY/Yd6vQclkqjBYONGN3r9R8bWA/0Y1j4XK61qjowRk3Iy8sBggM3PmmNRUJYgroerpcAr 2byz6wTsb3U7OzUZ1Llgisk5Qum0RN77m3I37FXlIhCmSEY7KZVzGNW3blugLHcfw/HuCB7R 1w5qiLWKK6eCQHL+BZwiU8hX3dtTq9d7WhRW5nsVPEaPqudQfMSi/Ux1kc0mQW5kcmVpIEJv cnplbmtvdiA8YXJ2aWRqYWFyQGdtYWlsLmNvbT7CZQQTEQIAJQIbAwYLCQgHAwIGFQgCCQoL BBYCAwECHgECF4AFAliWAiQCGQEACgkQR6LMutpd94wFGwCeNuQnMDxve/Fo3EvYIkAOn+zE 21cAnRCQTXd1hTgcRHfpArEd/Rcb5+SczsBNBDxiRyQQBACQtME33UHfFOCApLki4kLFrIw1 5A5asua10jm5It+hxzI9jDR9/bNEKDTKSciHnM7aRUggLwTt+6CXkMy8an+tVqGL/MvDc4/R KKlZxj39xP7wVXdt8y1ciY4ZqqZf3tmmSN9DlLcZJIOT82DaJZuvr7UJ7rLzBFbAUh4yRKaN nwADBwQAjNvMr/KBcGsV/UvxZSm/mdpvUPtcw9qmbxCrqFQoB6TmoZ7F6wp/rL3TkQ5UElPR gsG12+Dk9GgRhnnxTHCFgN1qTiZNX4YIFpNrd0au3W/Xko79L0c4/49ten5OrFI/psx53fhY vLYfkJnc62h8hiNeM6kqYa/x0BEddu92ZG7CRgQYEQIABgUCPGJHJAAKCRBHosy62l33jMhd AJ48P7WDvKLQQ5MKnn2D/TI337uA/gCgn5mnvm4SBctbhaSBgckRmgSxfwQ= Message-ID: <4dd4d78b-3bc5-3fd3-d44f-c1e259537b0e@gmail.com> Date: Sat, 18 Jan 2020 22:20:18 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Recently Ubuntu released kernel 5.3 for 18.04 LTS and I immediately started observing periodic stalls/freezes without any change in my normal usage pattern. The effects I noticed: - mouse is frozen for couple of seconds - keyboard input is frozen for couple of seconds - video freezes for a couple of seconds After some searching and experiments all those freezes look associated with swap usage. To make it absolutely clear - when this happens there is *NO* memory shortage. The situation is really - as soon as _some_ swap is being used, I start to see observed effects. It is enough to have several megabytes of used swap for this. I have a lot of free memory when this happens. Like total used free shared buff/cache available Mem: 7.7G 1.7G 3.6G 419M 2.4G 5.2G Swap: 15G 218M 15G This is trivially demonstrated by removing swap when stuttering is observed. Without any change in workload stuttering immediately disappears. If I add swap back, I again observe stuttering as soon as even minimal amount of swap is allocated. I tested also 5.4.13 which shows the same problem. From practical point of view it seems to be less eager to use swap, so at first it looks like problem is fixed; but if I force it to allocate swap (by starting several VM as example) I again see the same freezes. I then went back to 5.0 and problem is gone. No matter how many processes I start there are no freezes. I do see obvious slowdown due to increased disk activity as memory consumption grows, but this is expected. To me this looks like rather serious regression. There seem to be quite a lot of posts about similar issues starting with 5.3. I understand that all this is pretty much unscientific. I am happy to collect whatever information may be required (including compiling custom kernel).