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 86C4CC43334 for ; Sun, 3 Jul 2022 15:07:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F27526B0072; Sun, 3 Jul 2022 11:07:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ED6E48E0001; Sun, 3 Jul 2022 11:07:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DC63A6B0074; Sun, 3 Jul 2022 11:07:50 -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 CA2FC6B0072 for ; Sun, 3 Jul 2022 11:07:50 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id 9F8BD80882 for ; Sun, 3 Jul 2022 15:07:50 +0000 (UTC) X-FDA: 79646118300.16.2162BB2 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by imf29.hostedemail.com (Postfix) with ESMTP id C123712000F for ; Sun, 3 Jul 2022 15:07:48 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R371e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0VIBrIff_1656860863; Received: from 30.0.187.160(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VIBrIff_1656860863) by smtp.aliyun-inc.com; Sun, 03 Jul 2022 23:07:44 +0800 Message-ID: <68a5286b-7ff3-2c4e-1ab2-305e7860a2f3@linux.alibaba.com> Date: Sun, 3 Jul 2022 23:07:47 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [RFC PATCH v3 2/3] mm: Add PUD level pagetable account To: Matthew Wilcox Cc: Mike Rapoport , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <6a6a768634b9ce8537154264e35e6a66a79b6ca8.1656586863.git.baolin.wang@linux.alibaba.com> <1234a28a-dca0-5836-9066-4ab2d4fbcc95@linux.alibaba.com> <17df0d3c-caaf-ee34-f702-1d4e7674887f@linux.alibaba.com> From: Baolin Wang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1656860870; 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=ukul5hL84KAjXultq0JpdFLXc/lcUuhqPVVbKd8B7is=; b=LcnbOhWKU3RAF5cQkbYP2BXupTFzv/vlMgJQKdZWmi36Ao20Lf4MnBlQKbf/Lf6TrhXtAV FA1R3ulI6ZOmTpfasxV3iGPXkv/rJ88TX0Egxgj3rwZjQOIYWybDtahBBEHYhTNp4G+J+5 ruxuIhcgsj87Zx+WWnGwu/jhZDUi7Ec= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1656860870; a=rsa-sha256; cv=none; b=1aEunfOf70Asl5efojFk+nLGAFkd5IYUFjnFTLgCNbycvjUv5sl8eUec5cp06q3hHBcGY+ fVyvZpl1E7qWaUTYi9GnXRwFrWLcw6jkkfqOALqKd0nhnuhmz2QO/DFJ11IDkVrtwt+XU4 PFuEP13TcpVaBPHsgj93zb0DjVONLBg= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=none; spf=pass (imf29.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.133 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=alibaba.com Authentication-Results: imf29.hostedemail.com; dkim=none; spf=pass (imf29.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.133 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=alibaba.com X-Rspamd-Server: rspam03 X-Rspam-User: X-Stat-Signature: a41k5pk7rjw9g5kedbprjwf8sddgr1o5 X-Rspamd-Queue-Id: C123712000F X-HE-Tag: 1656860868-950186 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 7/3/2022 10:52 PM, Matthew Wilcox wrote: > On Sun, Jul 03, 2022 at 10:06:32PM +0800, Baolin Wang wrote: >> So for kernel pte page table allocation, I need another similar helpers like >> below. However they do the samething with >> pgtable_pud_page_ctor/pgtable_pud_page_dtor, so I am not sure this is good >> for adding these duplicate code. > > Why do we want to account kernel PTE page tables in NR_PAGETABLE? > I think that's confusing. Why this will confuse you? I think it is inconsistent that kernel PTE page tables are not accounted, because we will account PMD/PUD level page tables no matter they are userspace pagetable pages or kernel pagetable pages. Moreover the the vmalloc()/vmap() can consume some kernel pagetable pages, which should be accounted.