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=-2.2 required=3.0 tests=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 3E3B9C76188 for ; Tue, 16 Jul 2019 08:39:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A59021721 for ; Tue, 16 Jul 2019 08:39:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727889AbfGPIjK (ORCPT ); Tue, 16 Jul 2019 04:39:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44484 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727105AbfGPIjK (ORCPT ); Tue, 16 Jul 2019 04:39:10 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 728233092640; Tue, 16 Jul 2019 08:39:10 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.136]) by smtp.corp.redhat.com (Postfix) with SMTP id 4CBBA60C44; Tue, 16 Jul 2019 08:39:09 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 16 Jul 2019 10:39:10 +0200 (CEST) Date: Tue, 16 Jul 2019 10:39:08 +0200 From: Oleg Nesterov To: Josef Bacik Cc: axboe@kernel.dk, linux-block@vger.kernel.org, kernel-team@fb.com, peterz@infradead.org Subject: Re: [PATCH 0/4][v2] rq-qos memory barrier shenanigans Message-ID: <20190716083907.GC15528@redhat.com> References: <20190715201120.72749-1-josef@toxicpanda.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190715201120.72749-1-josef@toxicpanda.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.43]); Tue, 16 Jul 2019 08:39:10 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 07/15, Josef Bacik wrote: > > This is the patch series to address the hang we saw in production because of > missed wakeups, and the other issues that Oleg noticed while reviewing the code. You missed another problem. See https://lore.kernel.org/linux-block/20190711114543.GA14901@redhat.com/ IOW, rq_qos_wait() needs set_current_state(TASK_UNINTERRUPTIBLE) after io_schedule(). Oleg.