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=-5.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 3D937C433DF for ; Sat, 6 Jun 2020 18:18:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13DCA20772 for ; Sat, 6 Jun 2020 18:18:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591467488; bh=t7wqDR7wEpns2huirFDRDLQiWcQrd8e54+X0JMUW6Vo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=DTMcC+eyKNP72dASQyZDOjoEuv9bxEMcKSqMpsx6aqTC5tyESC5rROK6o+InHqJ0u 0a3kuAwF707tVEM8Vkv4+mm4XsBIJ1tbLIS3lBDnE/eMASezLTFQgNrxJYaqHRHYFY Mb4FFiltZw3HCL0R3VyUtKu+Wq0BAgJ4Wy12iofM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728862AbgFFSSG (ORCPT ); Sat, 6 Jun 2020 14:18:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:55734 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728812AbgFFSSF (ORCPT ); Sat, 6 Jun 2020 14:18:05 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5B90F20760; Sat, 6 Jun 2020 18:18:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591467485; bh=t7wqDR7wEpns2huirFDRDLQiWcQrd8e54+X0JMUW6Vo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kwL0lZUyXV0DEXw6C8dg4xkl5oazFJEOP+uolRlYR2lgWX0IoRldzE/MGpV2ioDjO r/atlR3Yn4wfwTFsrQ+4GY01+XIyfosXielabV68cCPMs+oxymAD6l0fKbKm8hr3EK bLob7rD/+ehH9LMIeyO0Jzf//5V8RvpdqCnvAlWo= Date: Sat, 6 Jun 2020 20:18:02 +0200 From: Greg Kroah-Hartman To: kernel test robot Cc: Ian Kent , Andrew Morton , Al Viro , Tejun Heo , Rick Lindsley , Stephen Rothwell , David Howells , Miklos Szeredi , linux-fsdevel , Kernel Mailing List , lkp@lists.01.org Subject: Re: [kernfs] ea7c5fc39a: stress-ng.stream.ops_per_sec 11827.2% improvement Message-ID: <20200606181802.GA15638@kroah.com> References: <159038562460.276051.5267555021380171295.stgit@mickey.themaw.net> <20200606155216.GU12456@shao2-debian> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200606155216.GU12456@shao2-debian> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 06, 2020 at 11:52:16PM +0800, kernel test robot wrote: > Greeting, > > FYI, we noticed a 11827.2% improvement of stress-ng.stream.ops_per_sec due to commit: > > > commit: ea7c5fc39ab005b501e0c7666c29db36321e4f74 ("[PATCH 1/4] kernfs: switch kernfs to use an rwsem") > url: https://github.com/0day-ci/linux/commits/Ian-Kent/kernfs-proposed-locking-and-concurrency-improvement/20200525-134849 > Seriously? That's a huge performance increase, and one that feels really odd. Why would a stress-ng test be touching sysfs? thanks, greg k-h