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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AFB48CD8CB9 for ; Tue, 9 Jun 2026 14:44:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 26EDC6B00AE; Tue, 9 Jun 2026 10:44:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 21F8C6B00B0; Tue, 9 Jun 2026 10:44:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 10E7E6B00B1; Tue, 9 Jun 2026 10:44:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id F10DD6B00AE for ; Tue, 9 Jun 2026 10:44:32 -0400 (EDT) Received: from smtpin02.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id AF1931C2D9D for ; Tue, 9 Jun 2026 14:44:32 +0000 (UTC) X-FDA: 84860645184.02.A4E4F36 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf24.hostedemail.com (Postfix) with ESMTP id 0192B180003 for ; Tue, 9 Jun 2026 14:44:30 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=EJKSK6tf; spf=pass (imf24.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1781016271; b=5wd+bppf+4ot5I0hbLClM02y1vnUizquqfzPIw/fvGJ9croRSbPNnNlyoMl+bi94Jweq+w WSMT8+CY0nXllxla7yDri7hFvgOODHBVk04QJyfkRecHc+XWdxgLW3SXcMFErKpIK63XA9 1aPxcwV8y7iwEX+HgLhNALjTZa3h/8o= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=EJKSK6tf; spf=pass (imf24.hostedemail.com: domain of ljs@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=ljs@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1781016271; 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=h/LTuxyle4YoYh6mY0LGl6PYWDtEkH8oJY1eKe6M/oM=; b=GIMjPnuU6ajbkspxey9kG7eP9SqmvXasq5VJtgfieceSh7kJqcOYwZS2+4jxOACOELGg4l Gyw7yvKl++L5UgtXUHqC0b0j9uHD1022f/Gk25UxEwjeAQNx1ogSrghO9Xtd79Wt6RDiZ5 w01X/7gnuPELNktR4bbmbNc2xcpEDIQ= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 3663D400AD; Tue, 9 Jun 2026 14:44:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D0C241F00893; Tue, 9 Jun 2026 14:44:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781016270; bh=h/LTuxyle4YoYh6mY0LGl6PYWDtEkH8oJY1eKe6M/oM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=EJKSK6tfVoJfiMgc65JDw1LIyZwhbCYFJ3Tz/3CwUMx3/5qsVcjmjKiAxzYA/3Qb4 QvQa4BIxuGn/y+ux8TJDW8wqnFVt4urkORkNhmAJlHwSGb1s5qzzX8ZlyIH98yBFRR MKvmBJgT0TdeXaF7HkAvPYUx9HKR9//s1yI96X9/4rTdJsxLuRZZLjxYp0kgk9tISF y1A9lH6yCx2M9/lCAm2cc24Ywpyr7XAnNyZZ//htrYoMku9+9uCsAhafxcYp5lGY2p J3HEhuZxvxK++83GrMDTzCCiMkAhd03bO1Of4cCFG3HwLQMOZecKuLqd5oF1Ik0svP JhWkimEXcNyiw== Date: Tue, 9 Jun 2026 15:44:21 +0100 From: Lorenzo Stoakes To: Nico Pache Cc: Luka Bai , David Hildenbrand , David Rientjes , linux-mm@kvack.org, Andrew Morton , Zi Yan , Baolin Wang , "Liam R. Howlett" , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kairui Song , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Rik van Riel , Harry Yoo , Jann Horn , Johannes Weiner , linux-kernel@vger.kernel.org, Luka Bai Subject: Re: [PATCH 0/5] mm/khugepaged: add collapse hint machanism for khugepaged and use in mglru Message-ID: References: <20260531-thp_collapse_hint-v1-0-866339cd4c2a@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 0192B180003 X-Rspam-User: X-Stat-Signature: w4x3ygg9tp8dwx98edffg9mpe796mxma X-HE-Tag: 1781016270-514831 X-HE-Meta: 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 vIDVfhvf m4nbfOr+hg5NOrkHFNIFX3WnOcqfCemTXVoIefpjLhFTqTzAgV77EM3qi+qATOUHDtCnukMKkBuoIVB51vi0j95AJRWZsa/pEBAL+GcGAck605zL3HAfCh4zm6UMBocHegcqX9r/aKfdfJKfIqChpEgZddm6NfCn14iLWZgQN1IzlUmchGlL1mqsGNLswd36/H+vBg6mhhIPwE1JlqoHKwqfcyc8j31hRj8lkiPNCYp3PKpcdAqUw2z7L0S0xjzjbWp0T Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Jun 09, 2026 at 04:17:45AM -0600, Nico Pache wrote: > I had future plans for something similar as part of the thp=auto work; > however that requires significant thought and investigation into how > we can properly gather hints for collapse/split THP candidates. From > my perspective we'd want a more global structure/system outside of > khugepaged, that would directly call khugepaged (and others like > split, etc). It would also tie into the allocator so that at fault > time it could leverage the hints to make better decisions. My fear > with this series is that making a decision now might complicate future > work by adding complexity we may eventually want to remove for a > better solution. I know this is future planning stuff, but I want to point out that we need to see significant rework of the THP code base before accepting any further major changes. > > If you have the chance perhaps you can lead a discussion on your > proposal at the biweekly MM alignment session. > > +David Rientjes as he leads those discussions. We could use that time > to layout a plan for what needs to be done for this work, and for the > work surrounding thp=auto as I beleive they will be interdependent :) We prefer to discuss THP topics in the THP cabal meeting, which both THP maintainers regularly attend :) having separate sessions we might not be aware of isn't really helpful. And 'THP auto' is a broad topic rather than a new feature. I don't think it should be seen as a topic 'owned' by anybody, but rather something that we as a community should discuss. Series that appear from nowhere trying to implement significant changes along those lines without community disucssion will not be hugely appreciated :) Thanks, Lorenzo