From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 983E86E9C8 for ; Fri, 2 Oct 2020 19:35:52 +0000 (UTC) Date: Fri, 02 Oct 2020 12:34:30 -0700 Message-ID: <87mu14pgl5.wl-ashutosh.dixit@intel.com> From: "Dixit, Ashutosh" In-Reply-To: <160163140103.4780.15903052662841878821@build.alporthouse.com> References: <20200930034029.64316-1-ashutosh.dixit@intel.com> <160163140103.4780.15903052662841878821@build.alporthouse.com> MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Subject: Re: [igt-dev] [PATCH i-g-t] lib/ioctl_wrappers: Keep IGT working without pread/pwrite ioctls List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" To: Chris Wilson Cc: igt-dev@lists.freedesktop.org List-ID: On Fri, 02 Oct 2020 02:36:41 -0700, Chris Wilson wrote: > > Quoting Ashutosh Dixit (2020-09-30 04:40:29) > > The general direction at this time is to phase out pread/write ioctls > > and not support them in future products. This means IGT must handle > > the absence of these ioctls. This patch does this by modifying > > gem_read() and gem_write() to do the read/write using the pread/pwrite > > ioctls first but when these ioctls are unavailable fall back to doing > > the read/write using a combination of mmap and memcpy. > > Note that not all pread/pwrite can be replaced by a mmap(bo) + mempcy. > Removing pread/pwrite support for arbitrary bo is a significant ABI > regression. Dave Airlie NAK'd pread/pwrite for discrete here: https://lists.freedesktop.org/archives/intel-gfx/2020-July/244677.html Also UMD's are not using them anymore so the thinking is we would discontinue pread/pwrite in i915 for future generations but retain them for previous generations. _______________________________________________ igt-dev mailing list igt-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/igt-dev