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 A1281C433F5 for ; Sun, 6 Mar 2022 03:21:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EB7A06B0071; Sat, 5 Mar 2022 22:21:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E653C6B0072; Sat, 5 Mar 2022 22:21:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D548C6B0073; Sat, 5 Mar 2022 22:21:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id C7BE46B0071 for ; Sat, 5 Mar 2022 22:21:56 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 9F8FB2085B for ; Sun, 6 Mar 2022 03:21:56 +0000 (UTC) X-FDA: 79212512232.14.79F0233 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf25.hostedemail.com (Postfix) with ESMTP id C7AFDA0002 for ; Sun, 6 Mar 2022 03:21:55 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 1EB81B80C0A; Sun, 6 Mar 2022 03:21:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BDEFC340F3; Sun, 6 Mar 2022 03:21:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646536912; bh=REVJSPu0LMK0qtybGjVcYKrtnj1nArD7KxhlEeXpL5g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FLMwT+NpOuEP0vOHJMxtaQQCN/mZaYJMCmAdZvyES6nO1Jm9Au4J35+ADH3prFkmM ZsC2YEFVN7imDE5s5m8f6PyDIVn26Y6IqFvrL83GF/k/fzjXYe3wb03jR5BRTgcRrr GplpnIQyNciooTCOdLNEMZ4J6FdjftAAzxXYLvLg5JuVN5xalRzaVfVDXNYEjymA2u G39goguDmEepx6hgQ/mKOml4CV+xaHXfjnm/O86YxVDqFDzM3UK9bjFVdOxTUxUeu7 yImes0TPKrEI4GAgeKyN+EY3e+9oLaGDV0HhAbva7R4LTpTZ+3MuNkaM5Do/Q61952 YLB3lWUFpmNpQ== Date: Sun, 6 Mar 2022 05:21:11 +0200 From: Jarkko Sakkinen To: Matthew Wilcox Cc: Andrew Morton , Dave Hansen , Nathaniel McCallum , Reinette Chatre , linux-sgx@vger.kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, codalist@coda.cs.cmu.edu, linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH RFC] mm: Add f_ops->populate() Message-ID: References: <20220306021534.83553-1-jarkko@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: C7AFDA0002 X-Stat-Signature: fm9uo4c1hmbm5pguksyi5tzap8aam1hz Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=FLMwT+Np; spf=pass (imf25.hostedemail.com: domain of jarkko@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=jarkko@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-HE-Tag: 1646536915-767891 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: On Sun, Mar 06, 2022 at 02:57:55AM +0000, Matthew Wilcox wrote: > On Sun, Mar 06, 2022 at 04:15:33AM +0200, Jarkko Sakkinen wrote: > > Sometimes you might want to use MAP_POPULATE to ask a device driver to > > initialize the device memory in some specific manner. SGX driver can use > > this to request more memory by issuing ENCLS[EAUG] x86 opcode for each > > page in the address range. > > > > Add f_ops->populate() with the same parameters as f_ops->mmap() and make > > it conditionally called inside call_mmap(). Update call sites > > accodingly. > > Your device driver has a ->mmap operation. Why does it need another > one? More explanation required here. f_ops->mmap() would require an additional parameter, which results heavy refactoring. struct file_operations has 1125 references in the kernel tree, so I decided to check this way around first. BR, Jarkko