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=-13.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 52F23C433B4 for ; Thu, 29 Apr 2021 23:22:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F63461261 for ; Thu, 29 Apr 2021 23:22:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229883AbhD2XXI (ORCPT ); Thu, 29 Apr 2021 19:23:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229582AbhD2XXG (ORCPT ); Thu, 29 Apr 2021 19:23:06 -0400 Received: from mail-qk1-x729.google.com (mail-qk1-x729.google.com [IPv6:2607:f8b0:4864:20::729]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2CD5C06138B for ; Thu, 29 Apr 2021 16:22:19 -0700 (PDT) Received: by mail-qk1-x729.google.com with SMTP id d19so33292427qkk.12 for ; Thu, 29 Apr 2021 16:22:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GQ8Jf74PNstibeAaTzLNuJjv1ieRo/LrsZj4933jgH4=; b=ioEyWjw0cDzGlWrSG3mnYuKT4D6gfMlwiW8DXYIjsB2B43S9kxcicSkdFWR/0Z6WOU SFl87W1FC4HYmPMKWb4t7H6lBhTBDkpV6gBpadi9DjvTC0nEWuq68NuiKO6TUSxsEi5p LLJ8rQAff+O29Rz4aCPz09oj5rhwS0CRCjzdNcvdDualg06ZfIF8Ik8ce0bgYHA5TJIb eZqQyneiYDh+uILhkNHTchuzp0qdcM+VasBgBb8g98vw3TPdUKSwDP/tvgY1/r7mXECb zRG2tZkYRE6vUp6V0Gdyj4cT4xiBJWyNNue80NDGnnyDFOl1zEXnBOz6eSJtLxEuqzGO NSgQ== 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:cc; bh=GQ8Jf74PNstibeAaTzLNuJjv1ieRo/LrsZj4933jgH4=; b=FRUH+xewiLZCWRwKBkxtit4Ef2ZxvebwnsHNVYGZNu2x9QtaokfC6aXFooJb9/tgI4 32krTX+M2LOjSolRiznsDshhgqPCrseOkBivEkVZPtmMQQtg0GuonPbjGxQ64SFiG+56 SD3ApQ2PEfDx0+50Y1hOJF1l91kFskWaOTKpjBddOdr4ByDjNz0VrQ1K5fWMg3Ws2nic gE7GqMF5rQobf1hjxXqbpKQiosm9Gqw8sR4r5FKrWmMOh86O/ccpbs0ziiC7l/SGSFdI oXLsSp79QdEAQtJ1CtqVw9DibeGLbm3bCwOmo33k3dey3cvx6o9r9OkzfaM7NY0FaKsP 3vcg== X-Gm-Message-State: AOAM530debZ6b4+X9wEMlKlGJL3GtKi0/AOey9dPLf8mxuPJsZWLO09G mpeAE+C4F70LrOQpzovhxYPa+r7PE8OStG11EmXa+Q== X-Google-Smtp-Source: ABdhPJwoSdIrhSptl+J44diCwPbOfm2eJTKr8USbzx3GQJ5xilS3WVn//b2z93oYw4IPCyuUiV3obqviDL20XT7QH8s= X-Received: by 2002:a37:41ce:: with SMTP id o197mr2365869qka.122.1619738535821; Thu, 29 Apr 2021 16:22:15 -0700 (PDT) MIME-Version: 1.0 References: <20210422120459.447350175@infradead.org> <20210422123308.196692074@infradead.org> <5c289c5a-a120-a1d0-ca89-2724a1445fe8@linux.intel.com> In-Reply-To: From: Josh Don Date: Thu, 29 Apr 2021 16:22:04 -0700 Message-ID: Subject: Re: [PATCH 04/19] sched: Prepare for Core-wide rq->lock To: Don Hiatt Cc: Aubrey Li , Aubrey Li , Peter Zijlstra , Joel Fernandes , "Hyser,Chris" , Ingo Molnar , Vincent Guittot , Valentin Schneider , Mel Gorman , linux-kernel , Thomas Gleixner Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 29, 2021 at 2:09 PM Don Hiatt wrote: > > On Thu, Apr 29, 2021 at 1:48 PM Josh Don wrote: > > > > On Wed, Apr 28, 2021 at 9:41 AM Don Hiatt wrote: > > > > > > I'm still seeing hard lockups while repeatedly setting cookies on qemu > > > processes even with > > > the updated patch. If there is any debug you'd like me to turn on, > > > just let me know. > > > > > > Thanks! > > > > > > don > > > > Thanks for the added context on your repro configuration. In addition > > to the updated patch from earlier, could you try the modification to > > double_rq_lock() from > > https://lkml.kernel.org/r/CABk29NuS-B3n4sbmavo0NDA1OCCsz6Zf2VDjjFQvAxBMQoJ_Lg@mail.gmail.com > > ? I have a feeling this is what's causing your lockup. > > > > Best, > > Josh > > Hi Josh, > > I've been running Aubrey+Peter's patch (attached) for almost 5 hours > and haven't had a single issue. :) > > I'm running a set-cookie script every 5 seconds on the two VMs (each > vm is running > 'sysbench --threads=1 --time=0 cpu run' to generate some load in the vm) and > I'm running two of the same sysbench runs on the HV while setting cookies > every 5 seconds. > > Unless I jinxed us it looks like a great fix. :) > > Let me know if there is anything else you'd like me to try. I'm going > to leave the tests running > and see what happens. I update with what I find. > > Thanks! > > don That's awesome news, thanks for validating. Note that with Aubrey's patch there is still a race window if sched core is being enabled/disabled (ie. if you alternate between there being some cookies in the system, and no cookies). In my reply I posted an alternative version to avoid that. If your script were to do the on-off flipping with the old patch, you'd might eventually see another lockup.