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=DKIM_SIGNED,DKIM_VALID, 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 6CD88C3A5A2 for ; Sun, 22 Sep 2019 15:52:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D626208C0 for ; Sun, 22 Sep 2019 15:52:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="QnVzUVvS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387541AbfIVPvr (ORCPT ); Sun, 22 Sep 2019 11:51:47 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:39673 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387494AbfIVPvr (ORCPT ); Sun, 22 Sep 2019 11:51:47 -0400 Received: by mail-pf1-f195.google.com with SMTP id v4so2840765pff.6 for ; Sun, 22 Sep 2019 08:51:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=cSJSMSobZih7iY3IhyRNQHQ9trYuF7BXMloT2eMFo9M=; b=QnVzUVvSs4BIFdsaW7E5fTuQQQprJgQTi9gtK1XEcjuRjNI/q/A9rVZ0G5aq1lFHlk CNsAWEFFLMuoXYKjrm1hJbfg/uwPplVRk03DqrAgaF7c31VDVbWXx9S5edh1qzxkXePy lzVsnBkCcE6dwe+Jld0ISy1dUEDSDGpUCkAXyxUQk9C1uxjnA5PUzETW2vU/zMHsvVCY GmWxDO3dbohqYhGdhQzSfUlzTcBkD7oBbSv8f1euSkyEyxbagwO/UQ/r2mIHMNR2aDkw qIa+Kc5LKpwlDCS5YDxXDpE9aV2iheJHk1yeBms5DWygFHMW/BrpEYa3hsAKMY0hTe/F HxbA== 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=cSJSMSobZih7iY3IhyRNQHQ9trYuF7BXMloT2eMFo9M=; b=Je9rWiPMcvNScQjReGNG6xPPKZuxjmQDnxbges9lcJy+pawY6DmxGIxWKFaMhOYVXo TXhq2qf6bT/31n2UAPKDK23b0itLQ96LV80QrFPQFdVOrU3mqgvgYpkQ6Tm0qaiFvhaQ TV0ZxUKH5nTV3MKXrTpkUwwPzmcW6CxPoREbnFTkZE9sxnJ2I238ip+ircxWhO7HmGhZ 68SEpsekNO96Gp5hN2U8gcly6Tiq3IYL/OtpSOog386w7oV43eGQupwRUbh5KtcCdhsa yxTyhFSxCL7ukvYSDLvSROPwGLz4AYfl/wIK730LZnalS7pyBqAqqGNMtDDIF1WQgHuc iYyA== X-Gm-Message-State: APjAAAU+LZXwi0nFcVRiR3LYCIh14DZylgWZfKma6auIE4Id6EyD/rDB UGPyns/AsXpXy37WryLynJ2Y9hnimcylxw== X-Google-Smtp-Source: APXvYqzvHZEqYuBfQuM7+ql9Sp59tQsGdv0b8NqPjLVSdDIFI68S8txssldHRXN1n25ugPJKCz2MzQ== X-Received: by 2002:a63:2884:: with SMTP id o126mr4154856pgo.279.1569167504896; Sun, 22 Sep 2019 08:51:44 -0700 (PDT) Received: from [192.168.1.188] ([66.219.217.79]) by smtp.gmail.com with ESMTPSA id i74sm11402148pfe.28.2019.09.22.08.51.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 22 Sep 2019 08:51:43 -0700 (PDT) Subject: Re: [PATCH v2 0/2] Optimise io_uring completion waiting To: "Pavel Begunkov (Silence)" , Ingo Molnar , Peter Zijlstra , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: From: Jens Axboe Message-ID: Date: Sun, 22 Sep 2019 09:51:41 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/22/19 2:08 AM, Pavel Begunkov (Silence) wrote: > From: Pavel Begunkov > > There could be a lot of overhead within generic wait_event_*() used for > waiting for large number of completions. The patchset removes much of > it by using custom wait event (wait_threshold). > > Synthetic test showed ~40% performance boost. (see patch 2) I'm fine with the io_uring side of things, but to queue this up we really need Peter or Ingo to sign off on the core wakeup bits... Peter? -- Jens Axboe