From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Subject: Re: [PATCH 2/2] mm: Consolidate page table accounting Date: Thu, 5 Oct 2017 13:10:48 +0300 Message-ID: <20171005101048.qa62lqk6gjfz6azt@node.shutemov.name> References: <20171004163648.11234-1-kirill.shutemov@linux.intel.com> <20171004163648.11234-2-kirill.shutemov@linux.intel.com> <3aabab03-7f0a-e82e-a1c2-79120aed5ace@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <3aabab03-7f0a-e82e-a1c2-79120aed5ace@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org To: Anshuman Khandual Cc: "Kirill A. Shutemov" , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Michal Hocko List-Id: linux-api@vger.kernel.org On Thu, Oct 05, 2017 at 10:38:29AM +0530, Anshuman Khandual wrote: > On 10/04/2017 10:06 PM, Kirill A. Shutemov wrote: > > This patch switches page table accounting to single counter from > > three -- nr_ptes, nr_pmds and nr_puds. > > > > mm->pgtables_bytes is now used to account page table levels. We use > > bytes, because page table size for different levels of page table tree > > may be different. > > > > The change has user-visible effect: we don't have VmPMD and VmPUD > > reported in /proc/[pid]/status. Not sure if anybody uses them. > > (As alternative, we can always report 0 kB for them.) > > > > OOM-killer report is also slightly changed: we now report pgtables_bytes > > instead of nr_ptes, nr_pmd, nr_puds. > > Could you please mention the motivation of doing this ? Why we are > consolidating the counters which also changes /proc/ interface as > well as OOM report ? What is the benefit ? Sure, I'll update description. -- Kirill A. Shutemov