From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx122.postini.com [74.125.245.122]) by kanga.kvack.org (Postfix) with SMTP id E81AE8D0002 for ; Fri, 11 May 2012 18:59:50 -0400 (EDT) Received: by qcsd16 with SMTP id d16so3158007qcs.14 for ; Fri, 11 May 2012 15:59:50 -0700 (PDT) Message-ID: <4FAD99E1.4090600@gmail.com> Date: Fri, 11 May 2012 18:59:45 -0400 From: KOSAKI Motohiro MIME-Version: 1.0 Subject: Re: [PATCH 2/2 v3] drm/exynos: added userptr feature. References: <1335188594-17454-4-git-send-email-inki.dae@samsung.com> <1336544259-17222-1-git-send-email-inki.dae@samsung.com> <1336544259-17222-3-git-send-email-inki.dae@samsung.com> <001501cd2e4d$c7dbc240$579346c0$%dae@samsung.com> <4FAB4AD8.2010200@kernel.org> <002401cd2e7a$1e8b0ed0$5ba12c70$%dae@samsung.com> <4FAB68CF.8000404@kernel.org> <4FAB782C.306@kernel.org> <003301cd2e89$13f78c00$3be6a400$%dae@samsung.com> <4FAC0091.7070606@gmail.com> <4FAC623E.7090209@kernel.org> <4FAC7EBA.1080708@gmail.com> <4FAD829E.2030707@gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Jerome Glisse Cc: KOSAKI Motohiro , Minchan Kim , Inki Dae , InKi Dae , airlied@linux.ie, dri-devel@lists.freedesktop.org, kyungmin.park@samsung.com, sw0312.kim@samsung.com, linux-mm@kvack.org > My point is this ioctl will be restricted to one user (Xserver if i > understand) and only this user, there is no fork in it so no need to > worry about fork, just setting the vma as locked will be enough. > > But i don't want people reading this driver suddenly think that what > it's doing is ok, it's not, it's hack and can never make to work > properly on a general case, that's why it needs a big comment stating, > stressing that. I just wanted to make sure Inki and Kyungmin > understood that this kind of ioctl should be restricted to carefully > selected user and that there is no way to make it general or reliable > outside that. first off, I'm not drm guy and then I don't intend to insist you. but if application don't use fork, get_user_pages() has no downside. I guess we don't need VM_LOCKED hack. but again, up to drm folks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org