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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29179C433EF for ; Wed, 8 Jun 2022 19:51:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9F9566B0072; Wed, 8 Jun 2022 15:51:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9D0D86B0073; Wed, 8 Jun 2022 15:51:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 897BA6B0074; Wed, 8 Jun 2022 15:51:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 7A6156B0072 for ; Wed, 8 Jun 2022 15:51:45 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id 500B7606AA for ; Wed, 8 Jun 2022 19:51:45 +0000 (UTC) X-FDA: 79556113770.29.387771B Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf18.hostedemail.com (Postfix) with ESMTP id 0456D1C0068 for ; Wed, 8 Jun 2022 19:51:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Zh6E1O/k4DCyLCNrPy8WRcNMDmgmQJh3yrbMqbEzUhs=; b=I7tvEA3+jYoN1tcr52ZiyNV/jy e6M7Ol0yCMQITuuaTrI2z3QK1k0Hp4oJpbEoYQW6eJeCG8HVEP0hVB+DqpEQOx1gDIivjOIUTr1RW Vy/gkl0wlffUTp+dG/2Icm5yzp1gz2xL6WknwUJq9KEhNh9yvXBHk0x1aeVrIMTFy6hrFN+o87EOo P3eag/CE0GD9mMv3dARWzEr5atGFN17FmRXU/2SEZfLRCHJ/SkGp/k0ufbdvMr0kSzQakpx8jav4i V6KCdevK8gxDl1oKe9LYvbQaQz1FU+PrbSKoHdh62zBQLOAisUicFi/HxX/lza1rghhLVEQLgIHD4 g4r7YplQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nz1iN-00CvOe-Qb; Wed, 08 Jun 2022 19:51:39 +0000 Date: Wed, 8 Jun 2022 20:51:39 +0100 From: Matthew Wilcox To: Linus Torvalds Cc: Ankur Arora , Linux Kernel Mailing List , Linux-MM , the arch/x86 maintainers , Andrew Morton , Mike Kravetz , Ingo Molnar , Andrew Lutomirski , Thomas Gleixner , Borislav Petkov , Peter Zijlstra , Andi Kleen , Arnd Bergmann , Jason Gunthorpe , jon.grimm@amd.com, Boris Ostrovsky , Konrad Rzeszutek Wilk , Joao Martins Subject: Re: [PATCH v3 00/21] huge page clearing optimizations Message-ID: References: <20220606202109.1306034-1-ankur.a.arora@oracle.com> <87k09s1pgo.fsf@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1654717905; a=rsa-sha256; cv=none; b=Q0bd8oQzS3Hpw7lDaQRaprngEWCM9BzntZXXsbZj+Xg5rBP1UGzisJM61LWh39YiLQz6Bv Fjgt5R2y0sBI/E3pE1J5uxPyUZYePC/I8LzIJNpXq/MWK0aWP7Sx6t4LadWmCQtigqCJ5h +viMYynvEzGVRF/LaKQ0ym18sESl4nU= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=I7tvEA3+; dmarc=none; spf=none (imf18.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1654717905; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Zh6E1O/k4DCyLCNrPy8WRcNMDmgmQJh3yrbMqbEzUhs=; b=NGJfDWlbAHSpQfVzFew51uf2r7Bp8rVBD/c8/GW0zbnTRHQilIWvl8bEmM9lphRKvs1Ftt DBOoiV99QFfdnuXhPvsMDYW6owKSSJQWMav0TZQLJB/SADtmcO5S5oVDKIBrVb1OR93jCl tT6cHcP/4Chl/A9HD+f79cdZugRL5Ew= X-Rspamd-Queue-Id: 0456D1C0068 X-Rspam-User: Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=I7tvEA3+; dmarc=none; spf=none (imf18.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Stat-Signature: cbquexfm158aqqg1byartw7d5pxzm91g X-Rspamd-Server: rspam02 X-HE-Tag: 1654717904-610445 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jun 08, 2022 at 08:49:57PM +0100, Matthew Wilcox wrote: > On Tue, Jun 07, 2022 at 10:56:01AM -0700, Linus Torvalds wrote: > > I worry a bit about the insanity of the "gigantic" pages, and the > > mem_map_next() games it plays, but that code is from 2008 and I really > > doubt it makes any sense to keep around at least for x86. The source > > of that abomination is powerpc, and I do not think that whole issue > > with MAX_ORDER_NR_PAGES makes any difference on x86, at least. > > Oh, argh, I meant to delete mem_map_next(), and forgot. > > If you need to use struct page (a later message hints you don't), just > use nth_page() directly. I optimised it so it's not painful except on > SPARSEMEM && !SPARSEMEM_VMEMMAP back in December in commit 659508f9c936. > And nobody cares about performance on SPARSEMEM && !SPARSEMEM_VMEMMAP > systems. Oops, wrong commit. I meant 1cfcee728391 from June 2021.