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=-5.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 3AA86C5B578 for ; Wed, 3 Jul 2019 07:17:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E2AF21897 for ; Wed, 3 Jul 2019 07:17:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="G1A9AYBK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727174AbfGCHRl (ORCPT ); Wed, 3 Jul 2019 03:17:41 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:35311 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbfGCHRl (ORCPT ); Wed, 3 Jul 2019 03:17:41 -0400 Received: by mail-pf1-f196.google.com with SMTP id d126so783410pfd.2 for ; Wed, 03 Jul 2019 00:17:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=iisGLnpDMCDcRGYnZFrm5QNOBopjV0PFBP/WVXC7UXs=; b=G1A9AYBKheMdFrnvN1YyO1MJLGjXEDLlSzS7pWcdPzD8H3eDh9cX1ySjCHXjZSiGQl znxHfP4GxqdPDd+d/tsGHq5GaPoiegA+hQU9sBBTXJqA510+yr7UsxW70ghiXYMvEgxh 1wnvoGFinNBNQfPzDnZW+yzYO6UBWF5YEEDxEE8UzxF0GG6oqPPOKiMdD51EzWGBWMpY /2DEz40WGLLb6JFmUYip8R9rp0U2LQF/x8KNCOh9D5HglfIItrkyj1o4p/j3XDZdbDnU jxeaDnXhltcEsiXt7LXVFYVrF7bQNMR7EGCF2CPpY03iRmvxMbsT/y9SufbVFVsWFO5v TYOw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=iisGLnpDMCDcRGYnZFrm5QNOBopjV0PFBP/WVXC7UXs=; b=m9Eq88r/sRdNqfhJ9Z//WBIT7VUfce670D2zV4NtmO2rz5WmNsVVDjVprjf8p1+HQZ VQYM7u8rtTiimylgjZnhx9Ru1udy9tC4QCXUAxhUj6OVSFZGijepANW9cSE6MpDediYi dDl3Luq0LEeoKC40YA2wPfCeTT62bvLJo2tw7bsdYDyuCYC+ipTuuie2rKbHbgtUDC14 zv9Cdj5XnDP3qOdcIy0QD7Dft28oVnJ3IyuHENSou5uwyP0ci/htb7DLt/RZzdGboPfe SA+JIFUl7gJXQ+/k5XBJG7iVKtMSyqj4IUUmhuYCBOj9i6P8huyK5lw0U5lvu4yjNUpl PcFg== X-Gm-Message-State: APjAAAXzq+d16nbUUV85Fq9TIWZQCOCec8a/l++9hDQMEqbAsDRytQZM Mt8xKPSJmAlCFKp+02YQJ84= X-Google-Smtp-Source: APXvYqxNMAsx58gkg+4a+u9KFhWHrEfwfu6HTSLrngVE9uUwVIVHTcYsa7TsuZwpHGst59l40NvRXw== X-Received: by 2002:a65:62c2:: with SMTP id m2mr35932735pgv.413.1562138260273; Wed, 03 Jul 2019 00:17:40 -0700 (PDT) Received: from localhost ([123.213.206.190]) by smtp.gmail.com with ESMTPSA id f19sm1663392pfk.180.2019.07.03.00.17.38 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 03 Jul 2019 00:17:39 -0700 (PDT) Date: Wed, 3 Jul 2019 16:17:37 +0900 From: Minwoo Im To: Chaitanya Kulkarni Cc: linux-block@vger.kernel.org, Minwoo Im Subject: Re: [PATCH] null_blk: add unlikely for REQ_OP_DISACRD handling Message-ID: <20190703071737.GD21258@minwoo-desktop> References: <20190702032027.24066-1-chaitanya.kulkarni@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190702032027.24066-1-chaitanya.kulkarni@wdc.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 19-07-01 20:20:27, Chaitanya Kulkarni wrote: > Since discard requests are not as common as read and write requests > mark REQ_OP_DISCARD condition unlikely in the null_handle_rq() and > null_handle_bio(). > > Signed-off-by: Chaitanya Kulkarni Chaitanya, Just a simple doubt here. I just have tested this patch with 'dd' to see any performance benefit when queue_mode == 0 || 1. But I don't think it's worth it for the performance of read/write OR I have an wrong way to test it. you have never mentioned performance in this patch, though. But, I do like this patch because it will indicate what you have mentioned in the commit message in the code level. Reviewed-by: Minwoo Im Thanks!