From patchwork Thu Apr 3 10:38:05 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Pankaj Raghav (Samsung)" X-Patchwork-Id: 14036759 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 08BC4C3600C for ; Thu, 3 Apr 2025 10:38:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DB0CD280003; Thu, 3 Apr 2025 06:38:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D601A280001; Thu, 3 Apr 2025 06:38:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C2782280003; Thu, 3 Apr 2025 06:38:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id A3FDF280001 for ; Thu, 3 Apr 2025 06:38:18 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 781E7160268 for ; Thu, 3 Apr 2025 10:38:18 +0000 (UTC) X-FDA: 83292383076.06.FFC6B95 Received: from mout-p-103.mailbox.org (mout-p-103.mailbox.org [80.241.56.161]) by imf17.hostedemail.com (Postfix) with ESMTP id C06BF4000C for ; Thu, 3 Apr 2025 10:38:16 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=pankajraghav.com header.s=MBO0001 header.b=ykqJVM+l; dmarc=pass (policy=quarantine) header.from=pankajraghav.com; spf=pass (imf17.hostedemail.com: domain of kernel@pankajraghav.com designates 80.241.56.161 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1743676697; 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-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=l+z1/Zyn5HmKuUJTv24M67f5IzWj0CacYuYhfJZ4e+M=; b=Nz6HooaoVLosZ2yCYldVCFEVavRIzouDXe9XnTL+aBUUsJ8MsgLiUFAK/qVUyS/tiVe1/5 gft+0TgI6KgHRCU/pX2C9Kx+f/ipEppfeGHZgVOJo8zx8HMpYW1lSTu+u1e+tgQSdCrgEi Poeuu++I56WjS/31PCafMkUaHLCIWUU= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=pankajraghav.com header.s=MBO0001 header.b=ykqJVM+l; dmarc=pass (policy=quarantine) header.from=pankajraghav.com; spf=pass (imf17.hostedemail.com: domain of kernel@pankajraghav.com designates 80.241.56.161 as permitted sender) smtp.mailfrom=kernel@pankajraghav.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1743676697; a=rsa-sha256; cv=none; b=2dEIyCz408LqLU15xGkduydv2uZGwrsJyVandXHlKGUNBtjgq+hqu8DjUnbp3YTetiZzWs JIuMlyeZcepTlgcRzDnZ+Y0MWUqCJXgdVN731elbmxA9huaVtZoneqGR01BMP4hBz1Zh1L W8f/AjqK+zXq9FHq5rwADGluNHoMNno= Received: from smtp102.mailbox.org (smtp102.mailbox.org [10.196.197.102]) (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 4ZSyr42sfXz9t0t; Thu, 3 Apr 2025 12:38:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pankajraghav.com; s=MBO0001; t=1743676692; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=l+z1/Zyn5HmKuUJTv24M67f5IzWj0CacYuYhfJZ4e+M=; b=ykqJVM+liavA+BklyaFz/qTCE1INxJagZrxrDAextxtobXTwLKKngkLlGMBAz+T4t/JMWF eY5jTWiUHIz9K6mZD4k79yF7CvFI6N7cW1RZ2Ou1ZMbNnOdonQ3LUjNCela9yEflAA47fx Qe69zUPV35avOcmymgZN/LB42qRdeaoWczKpbcppFmH2ZqA2+eIDcqFx1VBHzZZh0QzeXo LbL8+LJ/IG7HZcIXb44B7CyOe5cE+g5svb7xO5PzsmBFx44QJRpJmZrVUokR3A3A0Oc2OM 4WLvFoiOz5Wujag+jlhoAt/8mUKkqoNfJvH9OgZefPFEAppRmnx5FmO7gNaWww== From: "Pankaj Raghav (Samsung)" To: Andrew Morton , Jonathan Corbet Cc: linux-kernel@vger.kernel.org, willy@infradead.org, linux-mm@kvack.org, David Hildenbrand , da.gomez@kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, linux-doc@vger.kernel.org, kernel@pankajraghav.com, Pankaj Raghav Subject: [PATCH] docs: update THP admin guide about non-tmpfs filesystem support Date: Thu, 3 Apr 2025 12:38:05 +0200 Message-ID: <20250403103805.173761-1-kernel@pankajraghav.com> MIME-Version: 1.0 X-Rspamd-Server: rspam01 X-Stat-Signature: cbsmw4prm3ubxubwwefkandg6dufwik9 X-Rspam-User: X-Rspamd-Queue-Id: C06BF4000C X-HE-Tag: 1743676696-558724 X-HE-Meta: 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 Sg7EeY/F BoqiVVbzPq8RtoWqLPVhSLwT1ubq0CNoNkMaZTdes1GBTrc1399t4jdAcuWyP5jtEdY/TVDcBoulDY83rXeLrBgSapBtHYq0yLVqDTpgzMUY68ya8PJ/JoiPOZhdnl9PV5wEtkTTAH5YHh5mOCVhmyV5FYbx+3TD2+BBtcVQvxe4JYa1mE3fOo/1dDvz6veSPeMjDiM2DIBuexB+RqpR8ucf2n9XvDHvoCDG91HHxbNvMgdBz7kTv/m14GPapGYrk7r86VRxx7OgdHWk= 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: From: Pankaj Raghav THP support for non-tmpfs filesystem has been around for some time now. Update the admin guide to reflect it. Signed-off-by: Pankaj Raghav Reviewed-by: Bagas Sanjaya --- Documentation/admin-guide/mm/transhuge.rst | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) base-commit: f0a16f5363325cc8d9382471cdc7b654c53254c9 diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index dff8d5985f0f..01b7ce90d693 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -12,8 +12,8 @@ using huge pages for the backing of virtual memory with huge pages that supports the automatic promotion and demotion of page sizes and without the shortcomings of hugetlbfs. -Currently THP only works for anonymous memory mappings and tmpfs/shmem. -But in the future it can expand to other filesystems. +Currently, THP only works for anonymous memory mappings, tmpfs/shmem and +filesystems that support large folios. .. note:: 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``. + 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