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 D8E02C982FF for ; Tue, 22 Sep 2026 12:33:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BFD426B009F; Tue, 22 Sep 2026 08:33:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B87BB6B00A0; Tue, 22 Sep 2026 08:33:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A4F266B00A1; Tue, 22 Sep 2026 08:33:54 -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 7B9FC6B009F for ; Tue, 22 Sep 2026 08:33:54 -0400 (EDT) Received: from smtpin30.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay09.hostedemail.com (Postfix) with ESMTP id EA2338046E for ; Tue, 22 Sep 2026 12:33:53 +0000 (UTC) X-FDA: 85241339946.30.FFEA3DA Received: from mail-m1602365243.xmail.ntesmail.com (mail-m1602365243.xmail.ntesmail.com [160.236.52.43]) by imf19.hostedemail.com (Postfix) with ESMTP id 03F2E1A0003 for ; Tue, 22 Sep 2026 12:33:48 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=none; spf=pass (imf19.hostedemail.com: domain of zhen.ni@easystack.cn designates 160.236.52.43 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=1790080432; 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=VgTQH4b1BJ6GTwNVxNedgXEIMab+EQPizdNbAYN5nEQ=; b=Jqmu4VRl4rqswFpObOv5uxk4rkGU9o31ywRH9EuCxTolnu95mEjZ3Ch8vMCaPkoRgpJ02/ zUCspGFMqbHy3QVjNkILWdNVqxqYpVBWKV5f7if1Sg69iSui96Z5NsZRVNKaHL/cDLIp5O DHaPWE+DcHbluz4oaaxULJIPnq3aXlA= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790080432; b=erWzQxYuLvSEc+qV+4Rae1MPbVPh2Ct+qAEZ/CkYertRKNDP5nGk95udI3ZOMZnlSGOJT9 i6S0bzMoeM1EjTAD4ARuDfrSz3hznOmmoORp0t0TLxvatqbRHX+fLBdYl0suwuc267XRCk ET2yXXqlPXlEbRco3pfKFGUBndCt+jY= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; spf=pass (imf19.hostedemail.com: domain of zhen.ni@easystack.cn designates 160.236.52.43 as permitted sender) smtp.mailfrom=zhen.ni@easystack.cn; dmarc=pass (policy=none) header.from=easystack.cn Received: from [192.168.0.59] (unknown [218.94.118.90]) by smtp.qiye.163.com (Hmail) with ESMTP id 1f642799d; Tue, 22 Sep 2026 20:33:41 +0800 (GMT+08:00) Message-ID: <0894f68a-9cef-47ac-bf8e-86cb18b6cf67@easystack.cn> Date: Tue, 22 Sep 2026 20:33:40 +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: Zi Yan Cc: "Lorenzo Stoakes (ARM)" , "David Hildenbrand (Arm)" , 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> <99a94068-ab37-47c0-878c-7c1ada5204b2@easystack.cn> <8997BF57-2124-4F71-9CEE-6F7D31A15D87@nvidia.com> From: "zhen.ni" In-Reply-To: <8997BF57-2124-4F71-9CEE-6F7D31A15D87@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-HM-Tid: 0aa0c91b8cd90229kunm1cdcecd753db0 X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFJQjdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVkaTR4eVktDSBpNHksZGUweHVYVFA kWGhdVGRETFhoSFyQUDg9ZV1kYEgtZQVlJSkNVQk9VSkpDVUJLWVdZFhoPEhUdFFlBWU9LSFVCQk lOS1VKS0tVSkJLQlkG X-Rspam-User: X-Stat-Signature: srre75senzsb34xyexrrrbjm9fpgg13d X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 03F2E1A0003 X-HE-Tag: 1790080428-549171 X-HE-Meta: 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 gAUBYAZD RIbTqNE16ECE0f/0VXC1RDaDh8eyMUaiPo0btIOFLbQLZWt1DMDI6znNWFHKG3JYWewBy6uUfQQ/04oHClqrFR0mZaedKXAYWgdrKTVuYSb2YjAgNKv7ltWtF/x5djwba3LswQerFHd6HycNIVjWigfSX3nCoMrw+YZIVdtYPpOnpkIkXdVK1MJQztA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 在 2026/9/22 00:25, Zi Yan 写道: > On 19 Sep 2026, at 22:11, zhen.ni wrote: > >> 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. > > Without attaching a BPF program, page_owner could still print to > the console, right? Otherwise, it will break existing users without a > BPF program. You could add a hook to decide where to print the results. > The existing console/debugfs path is untouched -- the BPF iterator is a new, opt-in channel that coexists with it. Without a program attached, page_owner behaves exactly as before. >> >> 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 > > > Best Regards, > Yan, Zi > > Thanks, Zhen