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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS 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 2B834C07E85 for ; Fri, 7 Dec 2018 16:41:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4CEF2081C for ; Fri, 7 Dec 2018 16:41:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4CEF2081C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=acm.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726055AbeLGQlY (ORCPT ); Fri, 7 Dec 2018 11:41:24 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:45456 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726053AbeLGQlY (ORCPT ); Fri, 7 Dec 2018 11:41:24 -0500 Received: by mail-pl1-f195.google.com with SMTP id a14so2058919plm.12 for ; Fri, 07 Dec 2018 08:41:23 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=p3B54Fz3zncSi29/5Nei8t4KaHbt1agP06LWR0MM+pw=; b=slOtpwfa0Aj3BWrLWyow69MbNT3Cm08l+Y8g4ihTDF8p2Mi1wk3TGaw8oL2K2Pb1ZK m1BbMhfqb9jhRJbtU1VvdvOGSNgWHmpD1t9Ltzk+M/v507m+t4/2FngZeoethTThoa8e gWEiN1vJeIu+6H0pUgOsqq9pw2PKfFjHZQ3r1Fgzmj0X7yiQKndOCFCQ5NpKlYzNNSoy CQCVjKhgoR6nDroVHDbT+U+ffBPoXSVlKe+Tqqw1MredfnvZbpytN0f1iErUHN9GVl80 51cnACQqS4SB1OoUUFJCY3ObqE8AQXGLjm7Aw3T+VAuh+Y9sNfMEvyhd6CLcQR7IdUP1 RvWA== X-Gm-Message-State: AA+aEWaI7ERY72CP/o5LQD14sOg4tFCpxuZSNuMXUM1QYbQxiMbuSQKb Flj94E3FO6aRYkZyffjVmMs= X-Google-Smtp-Source: AFSGD/UCz4Hd6Gzgwcs9RUcXsRuox+NF7xFtAT+T179n46LudnUU4oFGz25f4HzX4dK2YietTSqfrg== X-Received: by 2002:a17:902:24d:: with SMTP id 71mr2704191plc.225.1544200882597; Fri, 07 Dec 2018 08:41:22 -0800 (PST) Received: from ?IPv6:2620:15c:2cd:203:5cdc:422c:7b28:ebb5? ([2620:15c:2cd:203:5cdc:422c:7b28:ebb5]) by smtp.gmail.com with ESMTPSA id i123sm6260775pfg.164.2018.12.07.08.41.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 07 Dec 2018 08:41:21 -0800 (PST) Message-ID: <1544200879.185366.314.camel@acm.org> Subject: Re: [PATCH v3] blk-mq: punt failed direct issue to dispatch list From: Bart Van Assche To: Jens Axboe , "linux-block@vger.kernel.org" Cc: Mike Snitzer , Ming Lei Date: Fri, 07 Dec 2018 08:41:19 -0800 In-Reply-To: <7eaf8a39-3628-e153-79c9-0f115a4392d4@kernel.dk> References: <1544199585.185366.303.camel@acm.org> <693ac87a-ebb5-2e4e-25e5-92a1d3865c8f@kernel.dk> <7eaf8a39-3628-e153-79c9-0f115a4392d4@kernel.dk> Content-Type: text/plain; charset="UTF-7" X-Mailer: Evolution 3.26.2-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, 2018-12-07 at 09:35 -0700, Jens Axboe wrote: +AD4 diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c +AD4 index 29bfe8017a2d..9e5bda8800f8 100644 +AD4 --- a/block/blk-mq-sched.c +AD4 +-+-+- b/block/blk-mq-sched.c +AD4 +AEAAQA -377,6 +-377,16 +AEAAQA void blk+AF8-mq+AF8-sched+AF8-insert+AF8-request(struct request +ACo-rq, bool at+AF8-head, +AD4 +AD4 WARN+AF8-ON(e +ACYAJg (rq-+AD4-tag +ACEAPQ -1))+ADs +AD4 +AD4 +- /+ACo +AD4 +- +ACo It's illegal to insert a request into the scheduler that has +AD4 +- +ACo been through -+AD4-queue+AF8-rq(). Warn for that case, and use a bypass +AD4 +- +ACo insert to be safe. +AD4 +- +ACo-/ Shouldn't this refer to requests that have been prepared instead of requests that have been through -+AD4-queue+AF8-rq()? I think this function is called for requests that are requeued. Requeued requests have been through -+AD4-queue+AF8-rq() but are unprepared before being requeued. Thanks, Bart.