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 610A0C982CC for ; Sun, 20 Sep 2026 02:11:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 47C066B0088; Sat, 19 Sep 2026 22:11:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 42C216B008A; Sat, 19 Sep 2026 22:11:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 31B006B008C; Sat, 19 Sep 2026 22:11:22 -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 068AD6B0088 for ; Sat, 19 Sep 2026 22:11:21 -0400 (EDT) Received: from smtpin03.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id D54DE1C2347 for ; Sun, 20 Sep 2026 02:11:20 +0000 (UTC) X-FDA: 85232513520.03.D5BA8EB Received: from mail-m2459.xmail.ntesmail.com (mail-m2459.xmail.ntesmail.com [45.195.24.59]) by imf11.hostedemail.com (Postfix) with ESMTP id 514B340005 for ; Sun, 20 Sep 2026 02:11:16 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=none; spf=pass (imf11.hostedemail.com: domain of zhen.ni@easystack.cn designates 45.195.24.59 as permitted sender) smtp.mailfrom=zhen.ni@easystack.cn; dmarc=pass (policy=none) header.from=easystack.cn ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789870279; b=0lrj6WiHvOx0++FhLzn1nxudjDOLEvuQ547p8XXKhnJA4TLVSoMsDvCD47jm22jpKTABEN grpkqpLPOqW9YQynUiQGisjmaAvgBdhPEMlUhsD737NDaQGVcH3+H/b5ytwkHesEtRlRIK JrWbmwzM/yxGL5hZEmqKfb5s8XZOV4g= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=none; spf=pass (imf11.hostedemail.com: domain of zhen.ni@easystack.cn designates 45.195.24.59 as permitted sender) smtp.mailfrom=zhen.ni@easystack.cn; dmarc=pass (policy=none) header.from=easystack.cn ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789870279; 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=O9TeQLRxH6Mh6I2pv/ZgHFSTRm6FYBfNDM2sqy7ZCH4=; b=ZQEUnEjvDL+04yFvkBJfpFzv+NbEcQhbJYPnlD3E23JbrthOuXcvDLyS6BLdx8Owu06/Iv /P6Zx0yNtF0lX5SyHIys+9lTj46cc0YjOwi4jk8qNrkE7rauLWd3wDS7TgPgpe4gPTLdyY pwHRBhPeecDuCJ4LrvCU7mIF0jaSmc0= Received: from [192.168.0.59] (unknown [218.94.118.90]) by smtp.qiye.163.com (Hmail) with ESMTP id 1f4881c20; Sun, 20 Sep 2026 10:11:10 +0800 (GMT+08:00) Message-ID: <99a94068-ab37-47c0-878c-7c1ada5204b2@easystack.cn> Date: Sun, 20 Sep 2026 10:11:10 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 0/8] mm/page_owner: Add PID/TGID/COMM and cgroup filtering To: "Lorenzo Stoakes (ARM)" , "David Hildenbrand (Arm)" Cc: Zi Yan , Andrew Morton , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Shuah Khan , Randy Dunlap , Brendan Jackman , Johannes Weiner , linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260907082620.2083838-1-zhen.ni@easystack.cn> <79548641-25f3-4ec3-a549-782fad168962@kernel.org> <6e8bfb0d-d595-4e6b-9536-0323ada57e25@easystack.cn> <22D1EC4B-FBCB-421E-B8DA-345B5F3505FB@nvidia.com> <98ca914b-4722-448d-b5a4-7f095d0ca433@kernel.org> From: "zhen.ni" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-HM-Tid: 0aa0bc94e7a60229kunm9a1984bc79d8c X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFJQjdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVkZQ09IVklJQ0JPSR8dSB9JQ1YVFA kWGhdVGRETFhoSFyQUDg9ZV1kYEgtZQVlJSkNVQk9VSkpDVUJLWVdZFhoPEhUdFFlBWU9LSFVKS0 lPT09IVUpLS1VKQktLWQY+ X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 514B340005 X-Stat-Signature: pujq7ic1aksk8onjko65hbhngcicdfjq X-Rspam-User: X-HE-Tag: 1789870276-139813 X-HE-Meta: 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 j5jSBOiQ ajZGmdtV55kq/adSki5TjAFnV1P5Z2XVNPDOoUyq5Ec429f5dXEGTxwji+HS/9N26oYDJzvs2UL5jkZv0/ZJSA7asY/9rFtyB4QAxM3jasnqU79h2v+BUmCHtFkeZ5jA5GN3D5hrB0pw44mHWQLzURpbUWdd2WTImg09H/EPqhilnGIxwJtKhDac2m8kq4GLptgvIkFqUvNrp6hoY62hZ1EqdpkqL/jWOehFi Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 在 2026/9/11 19:32, Lorenzo Stoakes (ARM) 写道: > On Fri, Sep 11, 2026 at 01:06:46PM +0200, David Hildenbrand (Arm) wrote: >> On 9/11/26 09:58, zhen.ni wrote: >>> >>> >>> 在 2026/9/9 23:54, Zi Yan 写道: >>>> On 9 Sep 2026, at 6:28, David Hildenbrand (Arm) wrote: >>>> >>>>> >>>>> Because it results in less kernel code  :) >>>>> >>>>> And less kernel code is good. Unless unavoidable. >>>> >>>> An alternative is to add BPF hooks like bpf_iter to do the filtering >>>> and by default, when no BPF program is attached, everything is printed. >>>> >>>> >>> >>> I’ve also thought about a similar approach—perhaps a new bpf_iter type >>> that could iterate over all pages by PFN. The advantage would be that >>> you can fully customize what you want to print and what you want to >>> filter. However, doing so would require refactoring the entire >>> page_owner, and I’m not sure whether it’s worth pursuing in this >>> direction.I’d also like to hear everyone’s thoughts on this. >> >> Certainly better than having more and more manual filters added to the code base. > > Agreed. > > bpf seems the ideal fit here I think? > > Means that those who want this information can get it and those who don't are > unaffected. > I have prototyped page_owner bpf_iter and confirmed it is a viable and valuable direction: 1.Most parameter parsing is offloaded to the existing BPF verifier, keeping the page_owner kernel-side logic simple. 2.Filtering and printing are delegated to the BPF program, providing greater flexibility and enabling more complex composite filtering. I plan to further refine this patch series, but it will likely be submitted as a separate series, as it represents a different direction. Thanks, Zhen