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=-5.8 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 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 8270FC4743C for ; Wed, 23 Jun 2021 16:55:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F13A611AD for ; Wed, 23 Jun 2021 16:55:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229926AbhFWQ5k (ORCPT ); Wed, 23 Jun 2021 12:57:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229726AbhFWQ5j (ORCPT ); Wed, 23 Jun 2021 12:57:39 -0400 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A53CBC061574 for ; Wed, 23 Jun 2021 09:55:21 -0700 (PDT) Received: by mail-lj1-x234.google.com with SMTP id d2so3853844ljj.11 for ; Wed, 23 Jun 2021 09:55:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ax+qMkz9tc+3GIw6VBZG84/vn46E053CBBShLS/lu7Y=; b=CueGo6nhL0ih/I8+FW2BDzxSi8s4y6185nndbX4VnBGU3Q0H2Dp7iJ49iu+3Go58DR yqUuhfV3Ox29PVtvujH9wwUuCShzRU8yiOVxzFinEjKUAJAS0aTMVkDBL/dqryqKGyky NpznK3UeD2MPMmPb/Lv+GFPLtebrapqwECa55UF+u7pJn21DUBY2OP+7tjRH3FyOCpuH WOA2/vw1hBW/rfog/bzKCiV5ZjXIf28yVBXXXuGxf3/e4kKGxkUCeGguZxtnd+TI0VuF +oL0McSqtoJmyHof+hJzkoDTkfVTXv2p9QvJiEJIrRbohBXdMIrZa5ojlZUh2rPjduL7 qDXw== 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=ax+qMkz9tc+3GIw6VBZG84/vn46E053CBBShLS/lu7Y=; b=bp+MAYbLSIMy36N4MWEnmcYBK9hALrwR9VNUg9AtqaTZpePISqcJ8Avu2IUywJ4qLA buNOLO5qEghstdXiu3Jb9bDrAGezSLd2mJyIjvHH9xF1a0eb9YfJE2Vv5BgV/PnfVp5C a0QMtiJp63yPGFhV3W6PvFuVb9hLZR67cVUyivwN4INOjMFews0HP96d4lMkMjjyotT/ 63j20EbCw3Ynlr0y1bIbowaEMWc4Ph23paEM0joOIcwxytwKKRwMxh3K+nbZQk0sEaqK cp/2L550WIvy+lmqj5M4YV2qsPItWy1+K5H6qMsb1FXafupsZREbQIsvHXQ4rM2nXKJj fdiA== X-Gm-Message-State: AOAM530YtyNSbvkc3pbQG4GtJJjj9VmxmkVrMgUUhZGgW1QcKdLsbqau JryYXdVXerizs6/uJO4TxPkj7tkjzy0Y+6kB2jB55Q== X-Google-Smtp-Source: ABdhPJxoNHsqS0Cspo6atJ2cS4VJgFv31o0Wr8mvnTzi19fZT73UHF2RR+bG/GciFyWIfq1NDhfzJrZct1B7Gxe2TMs= X-Received: by 2002:a2e:90ca:: with SMTP id o10mr476096ljg.299.1624467318567; Wed, 23 Jun 2021 09:55:18 -0700 (PDT) MIME-Version: 1.0 References: <2ED1BDF5-BC0C-47CD-8F33-9A46C738F8CF@linux.vnet.ibm.com> <20210622143154.GA804@vingu-book> <53968DDE-9E93-4CB4-B5E4-526230B6E154@linux.vnet.ibm.com> <20210623071935.GA29143@vingu-book> <6C676AB3-5D06-471A-8715-60AABEBBE392@linux.vnet.ibm.com> <20210623120835.GB29143@vingu-book> <5D874F72-B575-4830-91C3-8814A2B371CD@linux.vnet.ibm.com> In-Reply-To: <5D874F72-B575-4830-91C3-8814A2B371CD@linux.vnet.ibm.com> From: Vincent Guittot Date: Wed, 23 Jun 2021 18:55:07 +0200 Message-ID: Subject: Re: [powerpc][next-20210621] WARNING at kernel/sched/fair.c:3277 during boot To: Sachin Sant Cc: Odin Ugedal , Linux Next Mailing List , linuxppc-dev@lists.ozlabs.org, open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 23 Jun 2021 at 18:46, Sachin Sant wrote: > > > > Ok. This becomes even more weird. Could you share your config file and more details about > > you setup ? > > > > Have you applied the patch below ? > > https://lore.kernel.org/lkml/20210621174330.11258-1-vincent.guittot@linaro.org/ > > > > Regarding the load_avg warning, I can see possible problem during attach. Could you add > > the patch below. The load_avg warning seems to happen during boot and sched_entity > > creation. > > > > Here is a summary of my testing. > > I have a POWER box with PowerVM hypervisor. On this box I have a logical partition(LPAR) or guest > (allocated with 32 cpus 90G memory) running linux-next. > > I started with a clean slate. > Moved to linux-next 5.13.0-rc7-next-20210622 as base code. > Applied patch #1 from Vincent which contains changes to dequeue_load_avg() > Applied patch #2 from Vincent which contains changes to enqueue_load_avg() > Applied patch #3 from Vincent which contains changes to attach_entity_load_avg() > Applied patch #4 from https://lore.kernel.org/lkml/20210621174330.11258-1-vincent.guittot@linaro.org/ > > With these changes applied I was still able to recreate the issue. I could see kernel warning > during boot. > > I then applied patch #5 from Odin which contains changes to update_cfs_rq_load_avg() > > With all the 5 patches applied I was able to boot the kernel without any warning messages. > I also ran scheduler related tests from ltp (./runltp -f sched) . All tests including cfs_bandwidth01 > ran successfully. No kernel warnings were observed. ok so Odin's patch fixes the problem which highlights that we overestimate _sum or don't sync _avg and _sum correctly I'm going to look at this further > > Have also attached .config in case it is useful. config has CONFIG_HZ_100=y Thanks, i will have a look > > Thanks > -Sachin >