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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22467C433EF for ; Thu, 7 Jul 2022 11:32:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230020AbiGGLcv (ORCPT ); Thu, 7 Jul 2022 07:32:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235038AbiGGLct (ORCPT ); Thu, 7 Jul 2022 07:32:49 -0400 Received: from out30-43.freemail.mail.aliyun.com (out30-43.freemail.mail.aliyun.com [115.124.30.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C18CD2FFF2; Thu, 7 Jul 2022 04:32:47 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=33;SR=0;TI=SMTPD_---0VIdIQWG_1657193558; Received: from 30.97.48.62(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VIdIQWG_1657193558) by smtp.aliyun-inc.com; Thu, 07 Jul 2022 19:32:40 +0800 Message-ID: Date: Thu, 7 Jul 2022 19:32:44 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH 0/3] Add PUD and kernel PTE level pagetable account To: Dave Hansen , akpm@linux-foundation.org Cc: rppt@linux.ibm.com, willy@infradead.org, will@kernel.org, aneesh.kumar@linux.ibm.com, npiggin@gmail.com, peterz@infradead.org, catalin.marinas@arm.com, chenhuacai@kernel.org, kernel@xen0n.name, tsbogend@alpha.franken.de, dave.hansen@linux.intel.com, luto@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, arnd@arndb.de, guoren@kernel.org, monstr@monstr.eu, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, x86@kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-csky@vger.kernel.org, openrisc@lists.librecores.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: From: Baolin Wang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-csky@vger.kernel.org On 7/6/2022 11:48 PM, Dave Hansen wrote: > On 7/6/22 01:59, Baolin Wang wrote: >> Now we will miss to account the PUD level pagetable and kernel PTE level >> pagetable, as well as missing to set the PG_table flags for these pagetable >> pages, which will get an inaccurate pagetable accounting, and miss >> PageTable() validation in some cases. So this patch set introduces new >> helpers to help to account PUD and kernel PTE pagetable pages. > > Could you explain the motivation for this series a bit more? Is there a > real-world problem that this fixes? Not fix real problem. The motivation is that making the pagetable accounting more accurate, which helps us to analyse the consumption of the pagetable pages in some cases, and maybe help to do some empty pagetable reclaiming in future.