From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anshuman Khandual Subject: Re: [PATCH 2/2] mm: Consolidate page table accounting Date: Thu, 5 Oct 2017 10:38:29 +0530 Message-ID: <3aabab03-7f0a-e82e-a1c2-79120aed5ace@linux.vnet.ibm.com> References: <20171004163648.11234-1-kirill.shutemov@linux.intel.com> <20171004163648.11234-2-kirill.shutemov@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171004163648.11234-2-kirill.shutemov-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Kirill A. Shutemov" , Andrew Morton Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko List-Id: linux-api@vger.kernel.org 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 ?