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 05F11C83F01 for ; Thu, 31 Aug 2023 12:29:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346245AbjHaM3u (ORCPT ); Thu, 31 Aug 2023 08:29:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231799AbjHaM3t (ORCPT ); Thu, 31 Aug 2023 08:29:49 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 817B719A for ; Thu, 31 Aug 2023 05:29:46 -0700 (PDT) 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=BTmtDO+xBZOfoQMGxZ2QpE27NcKVMjWoTS63e1aA26k=; b=jAhYpYq95b8S5ZQX9DMO8BVPEE BK5PM8iV2xU7p3qYU8bQn7a+iGSAI6iSCeA+soBPAYbx1mtfJQNqMmzs+f/SvbqUHbgq1jZ4m6Fdd 4398M+N049JigIdBj7+tH0A5SHgugl56okhVuoHt3OxbPZAAeD5HYy3J2cBESDiatT4GFnnqx5iEX duGznyfgDRqTqmz+YQNRibyuBwICNagI+O+ABmeUwHXvljcY2uAcyhOslLi+dSdKy44yz4hDYOWvd BuMz+MjcsiM9k4jbIs2kbRRzPTFS5A8FxFfGn6ps3HruAH0Fwqm6UtXRW/p3QBg+nRUksQFMZGO0j PoLA0KgA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qbgnc-001HfL-Um; Thu, 31 Aug 2023 12:29:25 +0000 Date: Thu, 31 Aug 2023 13:29:24 +0100 From: Matthew Wilcox To: David Hildenbrand Cc: "Huang, Ying" , Ryan Roberts , Andrew Morton , Yin Fengwei , Yu Zhao , Catalin Marinas , Anshuman Khandual , Yang Shi , Zi Yan , Luis Chamberlain , Itaru Kitayama , "Kirill A. Shutemov" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v5 3/5] mm: LARGE_ANON_FOLIO for improved performance Message-ID: References: <20230810142942.3169679-1-ryan.roberts@arm.com> <20230810142942.3169679-4-ryan.roberts@arm.com> <87v8dg6lfu.fsf@yhuang6-desk2.ccr.corp.intel.com> <5c9ba378-2920-4892-bdf0-174e47d528b7@arm.com> <87cyz43s63.fsf@yhuang6-desk2.ccr.corp.intel.com> <4e14730b-4e4c-de30-04bb-9f3ec4a93754@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4e14730b-4e4c-de30-04bb-9f3ec4a93754@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 31, 2023 at 09:57:46AM +0200, David Hildenbrand wrote: > As raised in another mail, we can then discuss > * how we want to call this feature (transparent large pages? there is > the concern that "THP" might confuse users. Maybe we can consider > "large" the more generic version and "huge" only PMD-size, TBD) > * how to expose it in stats towards the user (e.g., /proc/meminfo) > * which minimal toggles we want > > I think there *really* has to be a way to disable it for a running system, > otherwise no distro will dare pulling it in, even after we figured out the > other stuff. > > Note that for the pagecache, large folios can be disabled and distributions > are actively making use of that. You can't. Well, you can for shmem/tmpfs, but you have to edit the source code or disable CONFIG_TRANSPARENT_HUGEPAGE to disable it for XFS.