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 D5F90C43334 for ; Mon, 11 Jul 2022 15:49:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 22B8B6B00E4; Mon, 11 Jul 2022 11:49:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1DB816B00E6; Mon, 11 Jul 2022 11:49:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0CAB96B00EA; Mon, 11 Jul 2022 11:49:16 -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 EDB766B00E4 for ; Mon, 11 Jul 2022 11:49:15 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay12.hostedemail.com (Postfix) with ESMTP id 35BB7120B63 for ; Mon, 11 Jul 2022 15:49:15 +0000 (UTC) X-FDA: 79675253070.03.5D0EB88 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf24.hostedemail.com (Postfix) with ESMTP id 86B57180065 for ; Mon, 11 Jul 2022 15:49:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=1kgE/Y6l01V6Wz1Edn/qbPsgnQsJgXCJQEDblFsTCVY=; b=AXL7o6/UZ6PDCaTIGgY7zzdx7t OkFNTHSsziCYPum+F0RkL/CD4h1q4U4dv2I3aJVszyapx5YKXQGx9DnI4Y38kEbatWmdglLEb7VTQ 4e17N0RGD0sybI7rIRB5wzyYm0VjwjA7RRp2z+Wmzo1xoNuEX90MwaPC40BAx/cwCjzb/yqn1cWD1 nWZwMzguNHUYEhvjop042jwsBtlsvyUwNZpYHmcEiL9+rZMk+OnucQCL9RpTj+XdnOAXq7Sk7Rkin /EfM0UvcSRSh5i8DRln5D1WXv3ANYAOoSSM8ifSA/goKIYg76xw3U7z0hChwFR3aYQYPiMWyVfskC UW2TSAKQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oAuui-002hCr-9j; Mon, 11 Jul 2022 15:01:32 +0000 Date: Mon, 11 Jul 2022 08:01:32 -0700 From: Christoph Hellwig To: Li Chen Cc: Catalin Marinas , Will Deacon , Rob Herring , Frank Rowand , Andrew Morton , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 0/4] add struct page and Direct I/O support to reserved memory Message-ID: References: <20220711122459.13773-1-me@linux.beauty> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220711122459.13773-1-me@linux.beauty> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b="AXL7o6/U"; dmarc=none; spf=none (imf24.hostedemail.com: domain of BATV+f255caa5280b39f3ab8c+6896+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+f255caa5280b39f3ab8c+6896+infradead.org+hch@bombadil.srs.infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657554554; 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=1kgE/Y6l01V6Wz1Edn/qbPsgnQsJgXCJQEDblFsTCVY=; b=N6MpcLj0SrKOZLmd3jk/ILZaoDBCrQOlFw8g/1bfBJ1/VTF+UW6qUINo4dAth9DDjtfBfF bkpnNOLkBQ6iTY370UGpFfWSewHpV5xOzJ00k3lT2A1urGHN+GxJ7EzKI6nTxPoR6rA1vV LqbjWdo7rW0afC9jqT5cELSLZ5kCab8= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657554554; a=rsa-sha256; cv=none; b=wnOwfsa8vOga97+bj+Y+qCC1NLTaCxLV1aq+gTX1MaIbywZEnzjYqqQKORkpCjTv0Gs37s OXDiOC6v/mlC6XNzXVb74HvdA6zNatBm+hRwSldTVt4eA2WP5N0wIJn0HabnuEn0PaWShA eOh1hzlzuq7km1abbomqh9toCuCZ1Pg= Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b="AXL7o6/U"; dmarc=none; spf=none (imf24.hostedemail.com: domain of BATV+f255caa5280b39f3ab8c+6896+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+f255caa5280b39f3ab8c+6896+infradead.org+hch@bombadil.srs.infradead.org X-Stat-Signature: 46p6cqkbiu8dartfr5dr6wuiy3azmhe8 X-Rspamd-Queue-Id: 86B57180065 X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1657554553-762777 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: Who is going to use it and how? Because normally the reserved memory is used through the DMA allocator, and you can't just do direct I/O to that.