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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D5E9C61D97 for ; Fri, 24 Nov 2023 15:54:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345963AbjKXPyD (ORCPT ); Fri, 24 Nov 2023 10:54:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345881AbjKXPx6 (ORCPT ); Fri, 24 Nov 2023 10:53:58 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67CF012B for ; Fri, 24 Nov 2023 07:54:04 -0800 (PST) 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=Yp/TRPnJUCRddcn2pwqpadteZMnyKo+3JgWlmsfeyA8=; b=hjzmSFaDj2EPMwg3j4Voli4wxk plO+mX85rqcIAExFojWw6zdP/4cQlZcoxhiqc/dZHaKeTy1dFmH6FGcUFX9UIh68Vtxk8ii3n/uqN /mW6X4/Asm/QMk7rs/H+oKD/H2s9KxNy2KiyIeq+6VMt+DrVDnyvF0UOpHMOmRfY9j4sI30NAaJsM KYPnt6dI6ZHzWFYk4hDSWR4ZfnhQryFDRZDI9fdi6YzGRsnbMly3QaU+KR3vL9cQefGVTXL2HADdz /uwm8AppmQCyNYeOvWJ4JC90e0208Tmwop3wGQi8w3dI+hBiJndFqYLAlKn+yFjFd8htpKXLT9b5f Rk61PzVA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1r6YUS-008icA-JD; Fri, 24 Nov 2023 15:53:12 +0000 Date: Fri, 24 Nov 2023 15:53:12 +0000 From: Matthew Wilcox To: David Hildenbrand Cc: Ryan Roberts , Andrew Morton , Yin Fengwei , Yu Zhao , Catalin Marinas , Anshuman Khandual , Yang Shi , "Huang, Ying" , Zi Yan , Luis Chamberlain , Itaru Kitayama , "Kirill A. Shutemov" , John Hubbard , David Rientjes , Vlastimil Babka , Hugh Dickins , Kefeng Wang , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RESEND PATCH v7 00/10] Small-sized THP for anonymous memory Message-ID: References: <20231122162950.3854897-1-ryan.roberts@arm.com> <9c8f6d2a-7ed8-45d2-9684-d77489bd99b8@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9c8f6d2a-7ed8-45d2-9684-d77489bd99b8@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 24, 2023 at 04:25:38PM +0100, David Hildenbrand wrote: > On 24.11.23 16:13, Matthew Wilcox wrote: > > On Fri, Nov 24, 2023 at 09:56:37AM +0000, Ryan Roberts wrote: > > > On 23/11/2023 15:59, Matthew Wilcox wrote: > > > > On Wed, Nov 22, 2023 at 04:29:40PM +0000, Ryan Roberts wrote: > > > > > This is v7 of a series to implement small-sized THP for anonymous memory > > > > > (previously called "large anonymous folios"). The objective of this is to > > > > > > > > I'm still against small-sized THP. We've now got people asking whether > > > > the THP counters should be updated when dealing with large folios that > > > > are smaller than PMD sized. It's sowing confusion, and we should go > > > > back to large anon folios as a name. > > > > > > I suspect I'm labouring the point here, but I'd like to drill into exactly what > > > you are objecting to. Is it: > > > > > > A) Using the name "small-sized THP" (which is currently only used in the commit > > > logs and a couple of times in the documentation). > > > > Yes, this is what I'm objecting to. > > I'll just repeat that "large anon folio" is misleading, because > * we already have "large anon folios" in hugetlb We do? Where? > * we already have PMD-sized "large anon folios" in THP Right, those are already accounted as THP, and that's what users expect. If we're allocating 1024 x 64kB chunks of memory, the user won't be able to distinguish that from 32 x 2MB chunks of memory, and yet the performance profile for some applications will be very different. > But inn the end, I don't care how we will call this in a commit message. > > Just sticking to what we have right now makes most sense to me. > > I know, as the creator of the term "folio" you have to object :P Sorry ;) I don't care if it's called something to do with folios or not. I am objecting to the use of the term "small THP" on the grounds of confusion and linguistic nonsense.