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 2C061C3600C for ; Thu, 3 Apr 2025 18:22:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 78A93280007; Thu, 3 Apr 2025 14:22:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 71177280005; Thu, 3 Apr 2025 14:22:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5B3D5280007; Thu, 3 Apr 2025 14:22:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 3A197280005 for ; Thu, 3 Apr 2025 14:22:11 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 0278BC0A12 for ; Thu, 3 Apr 2025 18:22:11 +0000 (UTC) X-FDA: 83293552104.25.0524FD2 Received: from mout-p-103.mailbox.org (mout-p-103.mailbox.org [80.241.56.161]) by imf06.hostedemail.com (Postfix) with ESMTP id 20C43180005 for ; Thu, 3 Apr 2025 18:22:09 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=pankajraghav.com header.s=MBO0001 header.b=ttXfk71o; spf=pass (imf06.hostedemail.com: domain of kernel@pankajraghav.com designates 80.241.56.161 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com; dmarc=pass (policy=quarantine) header.from=pankajraghav.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1743704530; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Uq27JMiTJIa5r25K1CbROwKYLHM43JGVKOiIpJ5rqG0=; b=cZVt287Va85w8iQAgQK4uzw6pAzgSqQMcuGDX0A+xVVXIFLuv22nvH59T5ThyMwBgxtqhk d0I6ba53Dwxrs9YgCevNeOkKuavebH5ANH/rWurap1Bvf/QVE5noUNCpCh21xpfs/zaIWQ 4PlBl+fG7LINKhrEGO5DMgIdqqHyyPQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1743704530; a=rsa-sha256; cv=none; b=NJbXjXoSAxOVMF36MI/dWds/xaE9RBNQoqt5F51zPYNLPgdHyt8kvqeOXQUrOaFXjS1Ww+ P5l+SSEfU2bFu0Mjlnz4yhYil0YxPaiZLrn8C3zD5K19f+q4qWDv+CUpf4wZqMDsZw7ic1 r44HVKTOdrPnrTIYMLYIIgbeHc9zquw= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=pankajraghav.com header.s=MBO0001 header.b=ttXfk71o; spf=pass (imf06.hostedemail.com: domain of kernel@pankajraghav.com designates 80.241.56.161 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com; dmarc=pass (policy=quarantine) header.from=pankajraghav.com Received: from smtp202.mailbox.org (smtp202.mailbox.org [10.196.197.202]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-103.mailbox.org (Postfix) with ESMTPS id 4ZT97K4Qxvz9tCK; Thu, 3 Apr 2025 20:22:05 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1743704525; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Uq27JMiTJIa5r25K1CbROwKYLHM43JGVKOiIpJ5rqG0=; b=ttXfk71oSpE/n07q4y88Uu+EdqXVL6GDvVu75W6YWmgCO+wqZG+A2enve1aQDWJtY0+37c IiGtmpp4iCrB/Pp19fqo/3PNN6CCjvkb0tkNxD+sw8onP8cS68HDQUTzIhf2Zlt9I3JULM ceIX5Mn6kI33dnEQuACHDvQ4TdGtB2pVTh5/adMS2Za3yF/aJZTioEMSwWVA4Zj2m0aW01 xASH3TnNkZ4fNLyYl46Eol7Eq2wQFXJK0P7VZI3ajr3EZiY77JmTVM9jOksW3W7O/5/+rP 17/On4GDG7Ke2MNIuFmSDIJ+gJxmFAihPnfhCTCGdh4x6vAXjl9qGD2ZefVHSw== Date: Thu, 3 Apr 2025 20:21:19 +0200 From: "Pankaj Raghav (Samsung)" To: David Hildenbrand Cc: Andrew Morton , Jonathan Corbet , linux-kernel@vger.kernel.org, willy@infradead.org, linux-mm@kvack.org, da.gomez@kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, linux-doc@vger.kernel.org, Pankaj Raghav Subject: Re: [PATCH] docs: update THP admin guide about non-tmpfs filesystem support Message-ID: References: <20250403103805.173761-1-kernel@pankajraghav.com> <77b19486-28ca-47e1-b506-6de604f6ec0a@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <77b19486-28ca-47e1-b506-6de604f6ec0a@redhat.com> X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 20C43180005 X-Stat-Signature: ajh98m5eqy7zoeb3pmm1gdns95cxooyw X-HE-Tag: 1743704529-710637 X-HE-Meta: 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 Ks/NcxWZ m6xZIQPqbPhiFYng9BTRvYXfB2U+SbxGv4/zWpGvAxKPtjHP3MmkMxQrbeyB4fPmRwmKSDrNp9Q69rZNFAAdVhnDX1+ltZBL4nMCf9CWs9/A4NVoNYg2XkCDs5LCRTFWkjCCg5lTEkAI+U/Es5knNr90CxM3Vghj8ruwWf0x6CZVT2s7JKiucdn51vUcJzR0Iia6+xfSSpattpNAslEI9pl5MKK8HEJqYSJSZ9cl7JRm1Ea+UQt71n8SMKg== 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: > > in the examples below we presume that the basic page size is 4K and > > @@ -463,6 +463,10 @@ fields for each mapping. (Note that AnonHugePages only applies to traditional > > PMD-sized THP for historical reasons and should have been called > > AnonHugePmdMapped). > > +The number of PMD-sized transparent huge pages currently used by > > +filesystem data (page cache) is available by reading the FileHugePages field > > +in ``/proc/meminfo``. > > + > > These changed look good. Do we also want to talk about FilePmdMapped? > (PMD-sized THPs in the page cache that are mapped in to user space using a > PMD ?) I am a bit new to this subsystem, and it took some time to wrap around all the different terminology used :) But sure, I will add a new commit to talk about FilePmdMapped. I can give it a shot with what I understand about FilePmdMapped, but please feel free to add your input. > > Do we have to distinguish it from below? (shmem also uses the page cache) > > > The number of file transparent huge pages mapped to userspace is available > > by reading ShmemPmdMapped and ShmemHugePages fields in ``/proc/meminfo``. > > To identify what applications are mapping file transparent huge pages, it > > Previously here, but: this reads rather odd. "file transparent huge pages". > "PMD-sized THPs specific to shmem are tracked separately ..." ? > I totally agree. Reading "file transparent huge pages" confused me even more. I will fold these changes as well. Thanks, David. -- Pankaj