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=-3.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,USER_AGENT_GIT autolearn=ham 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 992B1C10F11 for ; Wed, 24 Apr 2019 11:19:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 673222089F for ; Wed, 24 Apr 2019 11:19:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=digitalocean.com header.i=@digitalocean.com header.b="XbQKZGHe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728195AbfDXLTe (ORCPT ); Wed, 24 Apr 2019 07:19:34 -0400 Received: from mail-it1-f194.google.com ([209.85.166.194]:54446 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726135AbfDXLTd (ORCPT ); Wed, 24 Apr 2019 07:19:33 -0400 Received: by mail-it1-f194.google.com with SMTP id a190so5596972ite.4 for ; Wed, 24 Apr 2019 04:19:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=digitalocean.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to; bh=89e+dSKzA5afsooadXFqIW/dhRPfNS/VO9cxUzIYJzA=; b=XbQKZGHeg3iLzUZ0V+4n6tNPHiHq1l7B8g05mD4Jgmgky8oRQ/hrTEvVZMrnxcS876 I6+4dsE34yBbDaZkExOPOX5ZTUGp2gxfGI12SYG9trTBzulifeNge8zoLtDE+ok60pFB G5/VYKZ0ETiuf76ntTsPaMdPYSAFvNFvz4nzY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to; bh=89e+dSKzA5afsooadXFqIW/dhRPfNS/VO9cxUzIYJzA=; b=oDmQ2pfjcsJwLSjL9uR3RnPuGRagEGS09/k/BWJ5QzJbhVR75KPmSEiTvK5pYcmRu6 ytEKceVNqlVxUnusZIwHy81mMgtTFCTsZoWG/5TxNYjT7kmVZLn8KWNhmElB0YrLQOdV PRMFTR/GkMpXmt1W5sjLc13lb4vmlQ2EqzC4aBJyT6BfPMFBBUEAKtT39J36dnve3pkI INYduxIuEbRUnPC8yK8oFaLSwxdd0r/m/4QTU1QDrZfJVduye19UA6hqyAskya1Y0h/j VPcJXeSj4SYVxq07WSWqtodbQkbro7mQW04zK4kfojBsippHpgSE7yQEtVWNPWgeSjFt JBuA== X-Gm-Message-State: APjAAAXIHdTJWyz2fRFa2d/ALmNgr4ZbyASS9rHGIZnWl9Is/7rnlWiT LKp1q9GReEal5etbECsWZQezSw== X-Google-Smtp-Source: APXvYqyeHKUZYfXK7lKk+BMUdr9nnjSAKhLSAmdvV4MYlklw8LFKnv5S0oXqJwnuVYz4vJDH5z8VpA== X-Received: by 2002:a24:7688:: with SMTP id z130mr5962841itb.57.1556104772835; Wed, 24 Apr 2019 04:19:32 -0700 (PDT) Received: from swap-tester ([178.128.225.14]) by smtp.gmail.com with ESMTPSA id r21sm8889191itb.35.2019.04.24.04.19.31 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 24 Apr 2019 04:19:32 -0700 (PDT) From: Vineeth Remanan Pillai To: Aubrey Li Cc: Vineeth Remanan Pillai , Nishanth Aravamudan , Julien Desfossez , Peter Zijlstra , Tim Chen , mingo@kernel.org, tglx@linutronix.de, pjt@google.com, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, subhra.mazumdar@oracle.com, fweisbec@gmail.com, keescook@chromium.org, kerrnel@google.com, Aaron Lu , Valentin Schneider , Mel Gorman , Pawan Gupta , Paolo Bonzini , Phil Auld Subject: Re: [RFC PATCH v2 00/17] Core scheduling v2 Date: Wed, 24 Apr 2019 11:19:13 +0000 Message-Id: <20190424111913.1386-1-vpillai@digitalocean.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Is this one missed? Or fixed with a better impl? > > The boot up CPUs don't match the possible cpu map, so the not onlined > CPU rq->core are not initialized, which causes NULL pointer dereference > panic in online_fair_sched_group(): > Thanks for pointing this out. I think the ideal fix would be to correctly initialize/cleanup the coresched attributes in the cpu hotplug code path so that lock could be taken successfully if the sibling is offlined/onlined after coresched was enabled. We are working on another bug related to hotplugpath and shall introduce the fix in v3. Thanks