From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 27 Sep 1999 15:31:28 -0400 (EDT) From: James Simmons Subject: Re: mm->mmap_sem In-Reply-To: <37EF30FF.456EBA6B@kieray1.p.y.ki.era.ericsson.se> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Marcus Sundberg Cc: linux-mm@kvack.org List-ID: > No, you are trying to do _mandatory_ locking enforced by the kernel. > For cooperative locking on sane GFX hardware a userspace spinlock is > indeed all that is required, but for the broken hardware you are talking > about kernel locking would be required. What are all the broken cards out their? I was reading my old Matrox Millenium I docs and even that card supports similutaneous access to the accel engine and framebuffer. If the number of cards that are that broken are small then I just will not support them. > This means that when the accel engine is initiated you must unmap all > pages of the framebuffer (8k pages on modern cards), install a no-page > handler and flush the TLBs of all processors. All the processors!! Thats really bad. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/