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 9EE1EC27C65 for ; Tue, 11 Jun 2024 22:30:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1D71A6B0100; Tue, 11 Jun 2024 18:30:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 186BB6B0101; Tue, 11 Jun 2024 18:30:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 026626B0102; Tue, 11 Jun 2024 18:30:08 -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 D78546B0100 for ; Tue, 11 Jun 2024 18:30:08 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 8CB34807BA for ; Tue, 11 Jun 2024 22:30:08 +0000 (UTC) X-FDA: 82220052096.07.090BF12 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf03.hostedemail.com (Postfix) with ESMTP id BC16E20008 for ; Tue, 11 Jun 2024 22:30:06 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=rrBTIbJm; spf=pass (imf03.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1718145006; a=rsa-sha256; cv=none; b=koXGf6We1moi+Ev+bOMSX3v15ikpCkhqtqZFX6rsCDVF7cAT3LzRQfq24UXewJCjGHhhMg HRyp8dV8Iynp78HR8BqH2Wr9dMScy+lFuCLbQOdz/F/0hcO1o/4JrCtrFXwszsMdnGjnvo FY2CGHhIK0Y1D1JZNal7UxfxIF19YxA= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=rrBTIbJm; spf=pass (imf03.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1718145006; 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:dkim-signature; bh=sA2NQz3BMkJpAeCH7QXVuj2zKNkKTVrSoogd/WP5elc=; b=8dKrrpaflBn1AFhTCsybZhi1R2wgphemed4SrxXQkKlHXleRd534STLXnADNR+nvxVPBJz h9UHO3Bph7AJyYrWzRlJfvXBLJkxZMmpjtudfhGniDpbSXBKKP0+ejmvm9AcZlMuU1+Lh+ oZCmbT/g2Jk+pk/Xxi0KtnjqXPWrjrk= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 806116118B; Tue, 11 Jun 2024 22:30:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3051BC2BD10; Tue, 11 Jun 2024 22:30:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1718145005; bh=9RXJ8a97DEsdxRhMEVTCKuqQFatSuESJfhweaOU60zc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rrBTIbJmVn6LABt41IeGe1RUdI5zTMXwNH0wPzMLe00Vo2dyQqKEqw6EnLSZoc+SE jI83hMTGeEmb6WxoVZjEkauQDro0orlF4+kVPLZow+ZEnGZXX2SZ7V8Ca2DjnyeL6+ 1fN/gsFFBSVJ+UnjfEWAtL0rtL70BnrFKvLLvdfs= Date: Tue, 11 Jun 2024 15:30:03 -0700 From: Andrew Morton To: Sourav Panda Cc: corbet@lwn.net, gregkh@linuxfoundation.org, rafael@kernel.org, mike.kravetz@oracle.com, muchun.song@linux.dev, rppt@kernel.org, david@redhat.com, rdunlap@infradead.org, chenlinxuan@uniontech.com, yang.yang29@zte.com.cn, tomas.mudrunka@gmail.com, bhelgaas@google.com, ivan@cloudflare.com, pasha.tatashin@soleen.com, yosryahmed@google.com, hannes@cmpxchg.org, shakeelb@google.com, kirill.shutemov@linux.intel.com, wangkefeng.wang@huawei.com, adobriyan@gmail.com, vbabka@suse.cz, Liam.Howlett@Oracle.com, surenb@google.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org, weixugc@google.com, David Rientjes Subject: Re: [PATCH v13] mm: report per-page metadata information Message-Id: <20240611153003.9f1b701e0ed28b129325128a@linux-foundation.org> In-Reply-To: <20240605222751.1406125-1-souravpanda@google.com> References: <20240605222751.1406125-1-souravpanda@google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: njp7m8it7ax85s5hyyn6o96k6ttiw9wo X-Rspamd-Queue-Id: BC16E20008 X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1718145006-354163 X-HE-Meta: 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 khXTxtyd JPSSLj+IuMSQEwjPvp+nnnNuJy+UkvxAk9QzuiWYjn4VEcflwKhx7trwhcJWTwiCDz636aiD4b2HPDd1LbFd+Hix81XaSSIs/J1g+ur6+A0OxKntJCBk7E6JZ5fJmjnLQrpjOS2VTq5ZxtiP3w2lO1M36n6Yw9zNj9gYIijvIBUS3ZXvSaYf9Ww3zvIVP9d5DYC93XNHO8+9896QvQsVMDM2gMT5PtUJ97MN//ie4A/UiOUepEqxQy/oO0B8X/FcUegY3t4WDGv/Cg9wmHUKrB1dnwQ1NABFeScqKE5zrQr7SnC0pz49u2D/xjsqBpQP8YsGj 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: List-Subscribe: List-Unsubscribe: On Wed, 5 Jun 2024 22:27:51 +0000 Sourav Panda wrote: > Today, we do not have any observability of per-page metadata > and how much it takes away from the machine capacity. Thus, > we want to describe the amount of memory that is going towards > per-page metadata, which can vary depending on build > configuration, machine architecture, and system use. > > This patch adds 2 fields to /proc/vmstat that can used as shown > below: > > Accounting per-page metadata allocated by boot-allocator: > /proc/vmstat:nr_memmap_boot * PAGE_SIZE > > Accounting per-page metadata allocated by buddy-allocator: > /proc/vmstat:nr_memmap * PAGE_SIZE > > Accounting total Perpage metadata allocated on the machine: > (/proc/vmstat:nr_memmap_boot + > /proc/vmstat:nr_memmap) * PAGE_SIZE Under what circumstances do these change? Only hotplug? It's nasty, but would it be sufficient to simply emit these numbers into dmesg when they change?