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=-16.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D06C3C433F5 for ; Tue, 14 Sep 2021 21:39:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B37F860E8B for ; Tue, 14 Sep 2021 21:39:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234675AbhINVkU (ORCPT ); Tue, 14 Sep 2021 17:40:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235026AbhINVkT (ORCPT ); Tue, 14 Sep 2021 17:40:19 -0400 Received: from mail-wr1-x432.google.com (mail-wr1-x432.google.com [IPv6:2a00:1450:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0202FC061574 for ; Tue, 14 Sep 2021 14:39:02 -0700 (PDT) Received: by mail-wr1-x432.google.com with SMTP id g16so520607wrb.3 for ; Tue, 14 Sep 2021 14:39:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=QD7OayhROXujehkI34HCX9N67G5oxmlfHwV2CUb2QUw=; b=ghsorgWps1wHJ/GE1owAIqir1YE47uIxOq2AXcG9+Sf0P3gfFKMw0NGsmrom0NivKM Bd+F4IjeUiifvJGOdEjI0abGmXkD9+bt7EzwlJq34psMKbIy6vgRFcCEiRZJbJBbXtm3 Cojzx+wQdGnDWqXwDpBzfzfVHjc1g9y/a040jHVm8ODdAt0MLU33awcvYpYw8HxdSxin 83ytg3JDJP9bUO2vi9XxZk+DecL+A+I5r/rgwUVv80B9x3Y9eTp7nnkilEpTICgbdkRm 5vDlEHfhcAlENY9jexMn4+uGjI8nIw/6wJS80JkONDXxCniJm26TjT2tUBv0BMBijbYv P6Lg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=QD7OayhROXujehkI34HCX9N67G5oxmlfHwV2CUb2QUw=; b=CqBGZjHdQU+xDPoyzkcBqxVOAWmPRG3qbH3DMbcnb4kj/HEw/E5Dlny4v6vTHpmYeZ LOKLMXHG1vwij/W9aBdwbeprrZ4YXp4B064XI1O98SPzvLpuBjE0rqqqhqjHPYUVGGcy osv8pjJZDVzaz7VHJ5oiqWa5Av/rEQ+3R6i41c1lz4UrQoMYDDCgR8WRU2XcqAAU0AXM A+13daE2tAQxHdj4udMkjGEm/pgzaDexqOeuYe58CeJcZJ31t9eU4mApNa2Nu7nMz0C9 oOq5GrmqaS0dp6H5mzm1D4lCLWfmLeFWNwEf/o8y9nqJ912yLiZuURhbViHm1a2IW3mJ I/Bg== X-Gm-Message-State: AOAM5314WoTs8pGVdPAna812qlgt33bXPrhGbqFpNwpXfkVDVtv7sk67 wnS2xQKynsCReGCo5g7PtW17p3RikbU= X-Google-Smtp-Source: ABdhPJy3zvKuJKDnzQa98tSLjq9ePSu5/8hnd9ii5Y+XRT6Yg1EzZTbf1su4QvuqE7BKLJ7E2UT6tw== X-Received: by 2002:adf:f208:: with SMTP id p8mr1216869wro.379.1631655540418; Tue, 14 Sep 2021 14:39:00 -0700 (PDT) Received: from [192.168.8.197] ([185.69.144.239]) by smtp.gmail.com with ESMTPSA id x5sm2078499wmk.32.2021.09.14.14.38.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 14 Sep 2021 14:38:59 -0700 (PDT) Subject: Re: [PATCH] null_blk: poll queue support To: Jens Axboe , "linux-block@vger.kernel.org" References: From: Pavel Begunkov Message-ID: <1a63be84-3024-722b-232b-90f606a2addd@gmail.com> Date: Tue, 14 Sep 2021 22:38:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 4/17/21 4:29 PM, Jens Axboe wrote: > There's currently no way to experiment with polled IO with null_blk, > which seems like an oversight. This patch adds support for polled IO. > We keep a list of issued IOs on submit, and then process that list > when mq_ops->poll() is invoked. That would be pretty useful to have. to fold in: diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index 5914fed8fa56..eb5cfe189e90 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -1508,7 +1508,7 @@ static int null_poll(struct blk_mq_hw_ctx *hctx) cmd = blk_mq_rq_to_pdu(req); cmd->error = null_process_cmd(cmd, req_op(req), blk_rq_pos(req), blk_rq_sectors(req)); - nullb_complete_cmd(cmd); + end_cmd(cmd); nr++; } > > A new parameter is added, poll_queues. It defaults to 1 like the > submit queues, meaning we'll have 1 poll queue available. > > Signed-off-by: Jens Axboe > > --- -- Pavel Begunkov