From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 14EEF19E812 for ; Tue, 30 Jul 2024 10:37:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722335823; cv=none; b=irykbN6oRnux4MaEMqq1aDjBvSEknlwlVEk6gBVR/J3VdXKXtqlfhqhIP2TbtGvWTMzON/EtFQa41kEm7kxeItVMC3WWKWhY4TbZJvh7WN5P0R40ZqnbqrX/fUaJLhNvj1231j0H/uuJpcHcefnFU5lbnsSVAj6n1P+MsUu6VQU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722335823; c=relaxed/simple; bh=kJsK2HC7bilt/BSEHQJYcDnbRJxZyZ9cUgXggKXJ2U0=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=pq8cmqXOwi1ehyLo8hIyeVwKYXy3YIBkfS8uHZr2Oh5oJqGYp7xOqfKDB7/eEEhFkGpDDXu/dlAIAHqt8Z/OrP+NrTWDn1EE0oX7IQ1FwqnlcWCqthQwjCbeHgFnIO7yb0pmrv9fxby/oCE+5oIuyuwAtEDmB3rniHxD4rEmRSs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fQX9eekP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fQX9eekP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4E24C4AF0B; Tue, 30 Jul 2024 10:37:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722335822; bh=kJsK2HC7bilt/BSEHQJYcDnbRJxZyZ9cUgXggKXJ2U0=; h=Date:From:To:Cc:In-Reply-To:References:Subject:From; b=fQX9eekPKzL8SjCldhl8puy0JLxz9/qnacUsJGL5wQZhZNkVtqyf/mTwrc4GoGuOm P2lhf1HUze39nU71gKiwarbEsd4ss5qVc8GDEurWtGAn0buJarYqV9YT/dqm1kDUO6 Gm+2p3z4RwL3LEVimneNfw4Evr08PEdKxQJ9zqOhc1/1h+E5nfCr5Lh+XDHdNM+Ry7 YBENQhgqdN4X0b9ZgFTBRvrpSdBBhndb88wqNpAWIXqHe/c3i11LAMoftYVNIpXK/o nEg+EwtYEhg6ONos3bZIpPvFqv4ZoOzfS+JvID0mMVbAc7wiAn38kTqG4yUS2IlBPX ODvaKcJXwMt3g== Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailfauth.nyi.internal (Postfix) with ESMTP id 6CD821200043; Tue, 30 Jul 2024 06:37:00 -0400 (EDT) Received: from imap51 ([10.202.2.101]) by compute4.internal (MEProxy); Tue, 30 Jul 2024 06:37:00 -0400 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeftddrjeeggdeftdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefoggffhffvvefkjghfufgtgfesthejredtredttdenucfhrhhomhepfdetrhhn ugcuuegvrhhgmhgrnhhnfdcuoegrrhhnugeskhgvrhhnvghlrdhorhhgqeenucggtffrrg htthgvrhhnpeejjeffteetfeetkeeijedugeeuvdfgfeefiedtudeikeeggeefkefhudfh lefhveenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpe grrhhnugdomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidquddvkeehudejtddv gedqvdekjedttddvieegqdgrrhhnugeppehkvghrnhgvlhdrohhrghesrghrnhgusgdrug gvpdhnsggprhgtphhtthhopedt X-ME-Proxy: Feedback-ID: i36794607:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 400F5B6008D; Tue, 30 Jul 2024 06:37:00 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Tue, 30 Jul 2024 12:36:39 +0200 From: "Arnd Bergmann" To: "Linus Torvalds" , "Lorenzo Stoakes" Cc: "David Laight" , "linux-kernel@vger.kernel.org" , "Matthew Wilcox" , "Christoph Hellwig" , "Andrew Morton" , "Andy Shevchenko" , "Dan Carpenter" , "Jason A . Donenfeld" , "pedro.falcato@gmail.com" , "Mateusz Guzik" , "linux-mm@kvack.org" Message-Id: In-Reply-To: References: <23bdb6fc8d884ceebeb6e8b8653b8cfe@AcuMS.aculab.com> <902a9bf3-9404-44e8-9063-03da3168146a@lucifer.local> <137646a7-7017-490d-be78-5bd5627609c3@lucifer.local> <36aa2cad-1db1-4abf-8dd2-fb20484aabc3@lucifer.local> <2f1be7ee-2d70-4dd3-bfa2-1b94a4fc5a66@lucifer.local> Subject: Re: [PATCH 0/7] minmax: reduce compilation time Content-Type: text/plain Content-Transfer-Encoding: 7bit On Tue, Jul 30, 2024, at 06:10, Linus Torvalds wrote: > > Of course, I never did any build timings. I'm not sure how much it > actually shows up on that level. A couple of bad cases won't be *that* > noticeable when most cases aren't too horrid. I did a little bit of build timing last week, which confirms exactly what you expect here: On individual files, the difference can easily be 1000x faster, like on that arch/x86/xen/setup.c file, but overall the difference in build speed for an allmodconfig or defconfig build was between 1% and 3%, depending on how many of the extreme cases are included. Of course, it would be easy to take one of the extreme cases and add another expansion that then drives the memory usage and/or compile time up to a point where the build fails. Arnd