From mboxrd@z Thu Jan 1 00:00:00 1970 From: Francisco Jerez Subject: Re: [PATCH] drm/ttm: Fix race condition in ttm_bo_delayed_delete Date: Thu, 21 Jan 2010 15:44:02 +0100 Message-ID: <87pr53ecwd.fsf@riseup.net> References: <1263840434-9113-1-git-send-email-luca@luca-barbieri.com> <4B56F401.8070700@vmware.com> <4B5764BA.7080801@vmware.com> <4B576FF5.9040907@shipmail.org> <4B584E48.8020806@shipmail.org> <87vdeveekk.fsf@riseup.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1136231777==" Return-path: In-Reply-To: (Luca Barbieri's message of "Thu, 21 Jan 2010 15:17:11 +0100") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Mime-version: 1.0 Sender: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Errors-To: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org To: Luca Barbieri Cc: Thomas Hellstrom , Thomas Hellstrom , "airlied-cv59FeDIM0c@public.gmane.org" , "nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org" , "dri-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org" List-Id: nouveau.vger.kernel.org --===============1136231777== Content-Type: multipart/signed; boundary="==-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" --==-=-= Content-Type: multipart/mixed; boundary="=-=-=" --=-=-= Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Luca Barbieri writes: >> Nvidia cards have a synchronization primitive that could be used to >> synchronize several FIFOs in hardware (AKA semaphores, see [1] for an >> example). > > Does this operate wholly on the GPU on all nVidia cards? > > It seems that at least on some GPUs this will trigger "software > methods" that are basically a way for the GPU to trigger an interrupt > and stop the FIFO until the CPU handles the interrupt and restarts it. > Yes, it could be handled without software methods, Maarten (CC'ed) was looking into this, IIRC. > Also, is there a way on nVidia cards to get interrupts on fences, but > only where the fence sequence number is higher than a dynamically set > value? (so that one could sleep for fence X without getting an > interrupt for every single fence before that) > > If not, it could possibly be hacked around by reading from a DMA > object at the address of the fence sequence number and then resizing > the DMA object so that addresses from a certain point on would trigger > a protection fault interrupt. I don't think you can safely modify a DMA object without stalling the card completely, but i think you could use e.g. PGRAPH NOTIFY interrupts and disable them by flipping a bit in PGRAPH when you stop caring about them. --=-=-=-- --==-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAktYaDIACgkQ196Zy2qEI5fP2gCcDm3VgbijRqzIS3UrBup02LOx 1VgAnAjJ+ES/rWyRPMRsuL3ycjYfZFl7 =TMox -----END PGP SIGNATURE----- --==-=-=-- --===============1136231777== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Nouveau mailing list Nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org http://lists.freedesktop.org/mailman/listinfo/nouveau --===============1136231777==--