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 615E0C433F5 for ; Tue, 5 Apr 2022 18:51:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F2E406B0072; Tue, 5 Apr 2022 14:50:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EDD9E6B0073; Tue, 5 Apr 2022 14:50:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D7F136B0074; Tue, 5 Apr 2022 14:50:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0224.hostedemail.com [216.40.44.224]) by kanga.kvack.org (Postfix) with ESMTP id C8E096B0072 for ; Tue, 5 Apr 2022 14:50:57 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 7CB641838E52B for ; Tue, 5 Apr 2022 18:50:47 +0000 (UTC) X-FDA: 79323716934.29.412D247 Received: from mail-pj1-f48.google.com (mail-pj1-f48.google.com [209.85.216.48]) by imf27.hostedemail.com (Postfix) with ESMTP id 0598040036 for ; Tue, 5 Apr 2022 18:50:46 +0000 (UTC) Received: by mail-pj1-f48.google.com with SMTP id h23-20020a17090a051700b001c9c1dd3acbso337875pjh.3 for ; Tue, 05 Apr 2022 11:50:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bII+JPpo5IH9mgrwvjzQUo8tjQFZBMZQwRPuej7AAhI=; b=JhnKFhyHjciKLHFUxXi/UkE6P1dEsxlHONapSmJt19/k29RmjgUAVYbH3BesEwxHrM nuNIoh8Ght/verLVCcyudWRbTuK5FB5gudUG6wfh5V1VAuQWy9TBV6zzGwym1GiydR03 vnd3aH+JrjMQfwQrsbFC9hq8xLKanduVOA/IqxyyGsIa5ifLQOmP1D8O/cYStr7eSdbC YVTaw4fYG41B2EiuL56o5RPNJ7vL2GVgZKtRNqqIw+9SAl7p/3ivqlUyj/V5mSoe0bUG hEZiL1xXFGX9YMwU5eHmsKruNMmxDqBv4xNEYyIZlXU9AWWlJscq27gS+fVn5TWRnDI1 gfTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=bII+JPpo5IH9mgrwvjzQUo8tjQFZBMZQwRPuej7AAhI=; b=PrJW/eAZvQZB6KCI98HY+1sWCULObWO4GJqJoT7Co3pS5UBm0MyWIIoTkxsxK9cAmx 9sWtPuoaGDz6jjy8Jb8bahwREYCtkBo14nAZUk4GTgSBN1eW0/jIWcbP/NXRxWywFo63 RmJGvb7rB/cVAhKa+6GS9/6eVNLxZ5AGgRSteQrDV+kG2TvDc2Ph02GRT/1fATbB4uwP IgmNv4kpv8HgPAfYSXitYDJbUqJOssGSTb3y1Kc8HmZ2NIogBOhsEFkDEycAQQvSztov 0w/AylLbNDS9sVkj0cMhDOqRuW8bo0TiQfKvSULY27QeTCYlqXlbaIeBzwDp4kcU/l5y igeg== X-Gm-Message-State: AOAM533f+++tCJJF2O3A68Tptg7zXZWCaxfrCadGbEcZsKA/W6pT3/Nn gVUDbl6j5JPev1aR+59+4J4jMoKXQPBBz01a9ctYuA== X-Google-Smtp-Source: ABdhPJzAdZ+bLj6sxMy6NCkl3KdGndxeFm7oJtsBN+yYBEgdhfx+bLXHx0hNFl6alDAGRZ4eV0ogNMdiDO3mkNfNJ6k= X-Received: by 2002:a17:902:8b88:b0:156:2b14:cb6e with SMTP id ay8-20020a1709028b8800b001562b14cb6emr4908764plb.14.1649184645775; Tue, 05 Apr 2022 11:50:45 -0700 (PDT) MIME-Version: 1.0 References: <20220404234154.1251388-1-yosryahmed@google.com> In-Reply-To: From: Yosry Ahmed Date: Tue, 5 Apr 2022 11:50:09 -0700 Message-ID: Subject: Re: [PATCH v2 0/5] KVM: mm: count KVM page table pages in pagetable stats To: Sean Christopherson Cc: Huacai Chen , Aleksandar Markovic , Anup Patel , Atish Patra , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , mizhang@google.com, David Matlack , kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-mips@vger.kernel.org, Linux-MM , Linux Kernel Mailing List , Shakeel Butt , Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: q1f76adikdqfw6zk6584gabw49ae4cuu Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=JhnKFhyH; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf27.hostedemail.com: domain of yosryahmed@google.com designates 209.85.216.48 as permitted sender) smtp.mailfrom=yosryahmed@google.com X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 0598040036 X-HE-Tag: 1649184646-570905 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: +Johannes Weiner +Michal Hocko +Roman Gushchin On Tue, Apr 5, 2022 at 11:45 AM Sean Christopherson wrote: > > On Mon, Apr 04, 2022, Yosry Ahmed wrote: > > We keep track of several kernel memory stats (total kernel memory, page > > tables, stack, vmalloc, etc) on multiple levels (global, per-node, > > per-memcg, etc). These stats give insights to users to how much memory > > is used by the kernel and for what purposes. > > > > Currently, memory used by kvm for its page tables is not accounted in > > the pagetable stats. This patch series accounts the memory pages used by > > KVM for page tables in those stats. > > It's still not obvious to me that piggybacking NR_PAGETABLE is desirable, probably > because I am quite clueless as to how these stats are used on the backend. E.g. > why not have a NR_SECONDARY_PAGETABLE entry to track pages used for secondary MMU > page tables? We can add NR_SECONDARY_PAGETABLE or even NR_KVM_PAGETABLE, but I am not sure whether this separation is desired on the MM side. Let's see what MM folks think about this.