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 BFFA0E7C4F5 for ; Thu, 5 Oct 2023 07:38:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 25C118D00B4; Thu, 5 Oct 2023 03:38:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1E5558D0002; Thu, 5 Oct 2023 03:38:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 086788D00B4; Thu, 5 Oct 2023 03:38:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id E91638D0002 for ; Thu, 5 Oct 2023 03:38:00 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id B500114015E for ; Thu, 5 Oct 2023 07:38:00 +0000 (UTC) X-FDA: 81310603920.13.4643B2D Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf23.hostedemail.com (Postfix) with ESMTP id DE56F140007 for ; Thu, 5 Oct 2023 07:37:58 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=none; spf=pass (imf23.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1696491479; a=rsa-sha256; cv=none; b=BnlZ/LpKYOXvMPFNxZDL3fOtZryAyIlEP5+SN+Hlb+EI5aAp9AAs2oggB9k3c8xYpCI11A U9qxnr5IGCQ0z4hgWmmGBiXbktsD6SzhSvNE2Og1lG4z8cgqyZROcTAYc8zWHjmfPRoj26 gSQWq3LjOg5sfGWTgB/wypNZhWmMpvA= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=none; spf=pass (imf23.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1696491479; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=72wq+CHlwhfAOPolWh2Lcl/oksIddASqhRLXYnpQp6E=; b=2a6KlBqHnZAgHX1EEzrxyeD5XDyyjfnIq+FKMKprD0Do2k7iH7xuwRFI+7ThkDAjHSSX3S ACLicX1dE+7AAmyIbvHQDZKxGRwkRcOX3VdEz35iYgYyW+BCOH08h7wXRIn6rF8SPOTtny RFZ25kCf1HKZHTtzwSPpWGxGfz3qVqI= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6789FC15; Thu, 5 Oct 2023 00:38:36 -0700 (PDT) Received: from [10.57.66.151] (unknown [10.57.66.151]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1C3A53F762; Thu, 5 Oct 2023 00:37:55 -0700 (PDT) Message-ID: <9d13a144-a36c-45d1-b7db-a08f84fa54ca@arm.com> Date: Thu, 5 Oct 2023 08:37:54 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: ANON_LARGE_FOLIOS meeting follow-up & refined proposal Content-Language: en-GB To: David Hildenbrand , John Hubbard , Matthew Wilcox , Yang Shi , "Yin, Fengwei" , Yu Zhao , Zi Yan , David Rientjes , Andrew Morton , Vlastimil Babka , "Kirill A. Shutemov" , Hugh Dickins Cc: Linux-MM References: <4966f496-9f71-460c-b2ab-8661384ce626@arm.com> <4830fb3e-4a35-4842-98f4-9e7baa0e692a@arm.com> <7301771f-d654-4e5a-a197-3a3d8750440c@nvidia.com> <92937776-1e16-47e5-bef9-4c1a04bc98c0@arm.com> <5fa4aa95-6982-7879-e067-69fdb8b76d01@redhat.com> <1b03f4d6-634d-4786-81a0-5a104799b125@arm.com> From: Ryan Roberts In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: DE56F140007 X-Stat-Signature: mn9rsbdr7pmn78hcp3mrxnnkp9p6qa35 X-HE-Tag: 1696491478-61138 X-HE-Meta: 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 op3KvAMr zM1n0z/IQoxLzYNV6Qi6r4153k+DYKPomDyUytFFK87SbEH2FGrGJqC5UQtD/cRsTBvV97Ng6S4XNX2UVTZXGMNshvSqZj/Fq46MZg+3FERB8+8/ORD5cuW9wrhxQx8+wHRA1wvVgzTx3BGE/sxUiuUQ/XEGmTptj/1l0CwyqeeJnOX/ooaKQX9RN64H1mpdz6BGYgpPNevtZ7DLqzzlkJZvPYfhtZxSakHozrC4chFqtiE3sJd/6q7SEWgGXhFNh6edR++gXcURy5IRxPVGBd1Oi8Zs/sFkILPAxPAuL40gvCZFLKkQP5ADbaA== 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 02/10/2023 13:58, David Hildenbrand wrote: >> [...] >> >> My concern is that the "fresh start" is not as simple as it appears. I've come >> to the conclusion that if we have a new interface, then it should really be a >> strict superset of THP to make it extensible in future. But that opens questions > > ^ +1 > >> about how you configure PMD-sized allocations when both interfaces disagree. For >> "enabled" its fairly straightforward; you can do a logical OR. But its less >> clear how to handle disagreement over defrag. And then you have huge_zero_page >> and khugepaged etc, which might just stay with THP. But eventually we will > > Probably we want everything that THP had (khugepaged, zeropage, ...) also on > some (selected?) smaller orders. > >> probably want to do async collapse for smaller order folios too, and at that >> point you have to duplicate all those controls... So I concluded that actually >> it is cleaner to just bolt on a small-order extension to THP. I've updated all >> the docs, and that was pretty simple to do, which usually suggests that the >> extension is purely additive and shouldn't be confusing. > > Fine with me. I don't quite like bitmaps exposed to user space, though. Just > having a user-readable list or a "directory" with various options as files might > be cleaner ... > >> >> Take a look at the patches, then make a judgement ;-) >> > > ... but we'll discuss it there :) > David, FYI, the patches are posted at [1] (you're cc'ed) and have been in mm-unstable for nearly a week - so I guess they will go to mm-stable soon by default. So if you want to object to any of it, now's the time ;-). [1] https://lore.kernel.org/linux-mm/20230929114421.3761121-1-ryan.roberts@arm.com/