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=-14.3 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=unavailable 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 47AB6C433E0 for ; Fri, 19 Feb 2021 19:46:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1670364EC0 for ; Fri, 19 Feb 2021 19:46:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229725AbhBSTqB (ORCPT ); Fri, 19 Feb 2021 14:46:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229555AbhBSTp5 (ORCPT ); Fri, 19 Feb 2021 14:45:57 -0500 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5689FC061574; Fri, 19 Feb 2021 11:45:17 -0800 (PST) Received: by mail-ej1-x631.google.com with SMTP id e13so12466766ejl.8; Fri, 19 Feb 2021 11:45:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=dUGdp3YLs2BZmXGrzi6F4KewLbPwl+iYjXY9YqwK4EA=; b=ieQKu6GJLnktpb9Vr9FZA7GT7LBi1QGxATM0BI5Dv1IOW62oY/lizln9L3RT0L7kbG 6y+YxqjEwb+kT00HLBc9vqKsJKEjf8hWk33VRiACWi7JX59qoAUNjCcSKwK0Ci5GBdaM vfV0nezZ9InK+J8d45uSMuJzBLZ/gYVPAf3kXJrdwzIr7qxoyHZXAl2jSoTMx2RaTpAr ZB64549+/QKvPzUOIqVDbUZgLEt5KhLMjDmuUgMR24EOdbqssUWzyeeG1MsaLreZWs9Z YohTb6tDUnt3WTRHJUQjFrlEVvXfAHMDQ3W180zsfi5rIRAaqLWQPTgGVOahn9Qw8UBj 0xVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; 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=dUGdp3YLs2BZmXGrzi6F4KewLbPwl+iYjXY9YqwK4EA=; b=t2gPjAZJ83CSMQiQSqeRJNTNa8SF98vVtFfKB8GfQBGNdBm7Ya/RcL8mYsplcseMPS nh1fGymHbJqzOdUxva2At4YejhlHcZfTQk298lh9zvtftHXEexvdQX/yn/YKtoSbQOX0 CtMsqHnSDWqJWVuo+vryb/+Fu5QK7dIuDDec3nh5Pxnd9VHgnA8LnsXzaaHHWmEDv+XV hjAMpzjDkdKHXg8JCM0h1D7FLbgq+C58DXUkWKUgwGOXnDGAjUVWr5TEXnlDFHCmgQlG Xq8DVLMj6V4A4xlxRlzxxO0g/cVdD3r2jc0hujHqXokvOX/GQtZnrdq3wyCBzHKSAZyq n/lQ== X-Gm-Message-State: AOAM531Rua7X3xxl6CSXh/bcHYIPf2CqD06U5xCavAgnD18jxoMGe0Xj Tij6oi6M4oJUfqfKctwA0+IcPVIGvQY= X-Google-Smtp-Source: ABdhPJxMiOQ+zcQgp/GNd7TWp7MKr5unkvzuNQR4WDiriUdaQlWISrS1Hh/McO8zxho6tI+25ecS/w== X-Received: by 2002:a17:907:78d5:: with SMTP id kv21mr10209054ejc.461.1613763916068; Fri, 19 Feb 2021 11:45:16 -0800 (PST) Received: from [192.168.178.40] (ipbcc06d06.dynamic.kabel-deutschland.de. [188.192.109.6]) by smtp.gmail.com with ESMTPSA id u18sm5119866ejc.76.2021.02.19.11.45.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 19 Feb 2021 11:45:15 -0800 (PST) Subject: Re: [PATCH 23/25] target_core_user: add backend plug/unplug callouts To: Mike Christie , mst@redhat.com, stefanha@redhat.com, Chaitanya.Kulkarni@wdc.com, hch@lst.de, loberman@redhat.com, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org References: <20210217202811.5575-1-michael.christie@oracle.com> <20210217202811.5575-24-michael.christie@oracle.com> From: Bodo Stroesser Message-ID: <3cb1059f-fbdd-499d-e59d-9fc3a6a0c1bf@gmail.com> Date: Fri, 19 Feb 2021 20:45:14 +0100 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: <20210217202811.5575-24-michael.christie@oracle.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 17.02.21 21:28, Mike Christie wrote: > This patch adds plug/unplug callouts for tcmu, so we can avoid the > number of times we switch to userspace. Using this driver with tcm > loop is a common config, and dependng on the nr_hw_queues > (nr_hw_queues=1 performs much better) and fio jobs (lower num jobs > around 4) this patch can increase IOPs by only around 5-10% because > we hit other issues like the big per tcmu device mutex. > > Signed-off-by: Mike Christie > --- > drivers/target/target_core_user.c | 27 +++++++++++++++++++++++++-- > 1 file changed, 25 insertions(+), 2 deletions(-) > Looks good. Reviewed-by: Bodo Stroesser