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=-5.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 7211DC433DB for ; Thu, 25 Feb 2021 10:51:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D03E64E4D for ; Thu, 25 Feb 2021 10:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231818AbhBYKus (ORCPT ); Thu, 25 Feb 2021 05:50:48 -0500 Received: from z11.mailgun.us ([104.130.96.11]:40464 "EHLO z11.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233451AbhBYKer (ORCPT ); Thu, 25 Feb 2021 05:34:47 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1614249261; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=QAKeyZ9Su/z8OtvrwFe6t2G9Ko/Uzum2N9syhdKBguA=; b=leDgD4PYsLht2X1NOOZsE05B1IJzYx7R/tJbRt6nKSTQKGz24cU7MTXE46pkxWZdLPrBmBWT TJm63zO2vU2mJRyMIRd3pzwXtgIbWddXLLlofz71BFFX/P/9w46ZgFqTCDz5/sDGC7R9oiby 5gA47uF6mweVqodE4aX2DHdE/lA= X-Mailgun-Sending-Ip: 104.130.96.11 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n05.prod.us-west-2.postgun.com with SMTP id 60377d13ba1dc157804ed56c (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 25 Feb 2021 10:33:55 GMT Sender: ylal=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 98A4AC433C6; Thu, 25 Feb 2021 10:33:55 +0000 (UTC) Received: from [192.168.0.106] (unknown [49.206.40.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: ylal) by smtp.codeaurora.org (Postfix) with ESMTPSA id F1D81C433CA; Thu, 25 Feb 2021 10:33:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org F1D81C433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=ylal@codeaurora.org Subject: Re: [PATCH] driver core: Use unbound workqueue for deferred probes To: Greg KH Cc: rafael@kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, pkondeti@codeaurora.org, neeraju@codeaurora.org References: <1614167749-22005-1-git-send-email-ylal@codeaurora.org> From: Yogesh Lal Message-ID: Date: Thu, 25 Feb 2021 16:03:50 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, On 2/24/2021 6:13 PM, Greg KH wrote: > On Wed, Feb 24, 2021 at 05:25:49PM +0530, Yogesh Lal wrote: >> Queue deferred driver probes on unbounded workqueue, to allow >> scheduler better manage scheduling of long running probes. > > Really? What does this change and help? What is the visable affect of > this patch? What problem does it solve? > We observed boot up improvement (~400 msec) when the deferred probe work is made unbound. This is due to scheduler moving the worker running deferred probe work to big CPUs. without this change, we see the worker is running on LITTLE CPU due to affinity. ​ Please let us now if there are any concerns/restrictions that deferred probe work should run only on pinned kworkers. Since this work runs deferred probe of several devices , the locality may not be that important Thanks Yogesh Lal > thanks, > > greg k-h > -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation