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=-5.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 1C00BC432BE for ; Wed, 4 Aug 2021 13:32:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0472A60E96 for ; Wed, 4 Aug 2021 13:32:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237900AbhHDNcy (ORCPT ); Wed, 4 Aug 2021 09:32:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237644AbhHDNcw (ORCPT ); Wed, 4 Aug 2021 09:32:52 -0400 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F276C061798 for ; Wed, 4 Aug 2021 06:32:40 -0700 (PDT) Received: by mail-pj1-x1029.google.com with SMTP id j18-20020a17090aeb12b029017737e6c349so5784915pjz.0 for ; Wed, 04 Aug 2021 06:32:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=85UHwPYLE5ZveQneqV4WLF2MU/xjzX/UPKrCzzHnB14=; b=q2ARy0ItDKIN/bKfZowVKNhSCk1iR23sFUCsXF9F5e2O8S7yQM9vDKyTDAU+cATUeB qcS46CMlVcYBPrL9nXZfr3FhktzUIvdNGGT00a9h9Yz65TDCpYXQqtFYQOi492pI8YU3 YjO2iNAJkR0KR4JEA9OJZGM4RfAg00/NNZoplDkoqEhP+7RZkIdnFWEaprwSBMV+Yw3H DryOMHYy/5SjMe1BCeh4DFSh42ZK4Sc+fSRiDk2lYuah2WinVjsJBAPizq8nOcCLAd7T xbn5JiNS8W6g3HCXlqvzmeUeckAh4NGYbS+8zfGS0pgWyj70SFdZHtynbJi65c2ecvH7 da9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=85UHwPYLE5ZveQneqV4WLF2MU/xjzX/UPKrCzzHnB14=; b=jOjk3qtmNxL2HcPbigdBbDvk86sC8uq2fmvNogriAvVwQkrzWktFyv7scOn+HxtwiM 7fKuO1Hci1lVxWU9fQQJxRp+QHgqTnQ6L78v3RKTJTUmQeCP9T2fOGct2MmcaJpPQkP+ LKSjEW1KP2oCTUNuX8aaSCncvQQ7v8UK68fERpsQiRGE2ejOj+pikg5+vayp5wsiI/aa 9h+FUJvticys6pIs7I+tjW3JdZdln35ZoCxwGMqsZMrQanv9GTG1IqVLYbZezYM3M9LY OlI2JjKzAJdtHckdIn8ykHWCH9c/J/+eTGVE+Sg2LbS2qRUkQTfcv6waYW+PQot/AizN /d8A== X-Gm-Message-State: AOAM533GwRt54PUfyrBB1gPzJLdYA/HIh4GUG4VZ8VCZsaIcnAWSBs75 JJ6VYfCMNO12HHAq9m4VhwXVnw== X-Google-Smtp-Source: ABdhPJzjzNXBg+QlL6+ONsT+jwbXMjDobWWv90yVRoQxU18drn+IHw5pzpernyaOISh3X6tOFb/NuA== X-Received: by 2002:a17:90a:4549:: with SMTP id r9mr28108180pjm.147.1628083959247; Wed, 04 Aug 2021 06:32:39 -0700 (PDT) Received: from [192.168.1.116] ([198.8.77.61]) by smtp.gmail.com with ESMTPSA id l14sm6249066pjz.19.2021.08.04.06.32.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Aug 2021 06:32:38 -0700 (PDT) Subject: Re: [ANNOUNCE] v5.14-rc4-rt4 To: Peter Zijlstra , Sebastian Andrzej Siewior Cc: Daniel Wagner , Thomas Gleixner , LKML , linux-rt-users@vger.kernel.org, Steven Rostedt References: <20210802162750.santic4y6lzcet5c@linutronix.de> <20210804082418.fbibprcwtzyt5qax@beryllium.lan> <20210804104340.fhdjwn3hruymu3ml@linutronix.de> <20210804104803.4nwxi74sa2vwiujd@linutronix.de> <20210804110057.chsvt7l5xpw7bo5r@linutronix.de> <20210804131731.GG8057@worktop.programming.kicks-ass.net> From: Jens Axboe Message-ID: <4f549344-1040-c677-6a6a-53e243c5f364@kernel.dk> Date: Wed, 4 Aug 2021 07:32:35 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210804131731.GG8057@worktop.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/4/21 7:17 AM, Peter Zijlstra wrote: > On Wed, Aug 04, 2021 at 01:00:57PM +0200, Sebastian Andrzej Siewior wrote: >> On 2021-08-04 12:48:05 [+0200], To Daniel Wagner wrote: >>> On 2021-08-04 12:43:42 [+0200], To Daniel Wagner wrote: >>>> Odd. Do you have a config for that, please? >>> >>> No need. >>> | [ 90.202543] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:35 >>> | [ 90.202549] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2047, name: iou-wrk-2041 >>> | [ 90.202555] CPU: 5 PID: 2047 Comm: iou-wrk-2041 Tainted: G W 5.14.0-rc4-rt4+ #89 >>> | [ 90.202561] Call Trace: >> … >>> | [ 90.202588] rt_spin_lock+0x19/0x70 >>> | [ 90.202593] ___slab_alloc+0xcb/0x7d0 >> … >>> | [ 90.202618] kmem_cache_alloc_trace+0x79/0x1f0 >>> | [ 90.202621] io_wqe_dec_running.isra.0+0x98/0xe0 >>> | [ 90.202625] io_wq_worker_sleeping+0x37/0x50 >>> | [ 90.202628] schedule+0x30/0xd0 >>> >>> le look. >> >> So this is due to commit >> 685fe7feedb96 ("io-wq: eliminate the need for a manager thread") >> >> introduced in the v5.13-rc1 merge window. The call chain is >> schedule() >> sched_submit_work() >> preempt_disable(); >> io_wq_worker_sleeping() >> raw_spin_lock_irq(&worker->wqe->lock); >> io_wqe_dec_running(worker); >> io_queue_worker_create() >> kmalloc(sizeof(*cwd), GFP_ATOMIC); >> >> The lock wqe::lock has been turned into a raw_spinlock_t in commit >> 95da84659226d ("io_wq: Make io_wqe::lock a raw_spinlock_t") >> >> after a careful analysis of the code at that time. This commit breaks >> things. Is this really needed? > > Urgh, doing allocs from schedule seems really yuck. Can we please not do > this? Agree, I have an idea of how to get rid of it. Let me experiment a bit... -- Jens Axboe