From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Peres Subject: Re: "enable ctxprog xfer only when we need it to save power" introduces big performance regression Date: Thu, 10 Nov 2011 08:10:44 +0100 Message-ID: <4EBB78F4.2020902@ensi-bourges.fr> References: <20111029170801.GA3219@joi.lan> <20111029172923.GA3110@joi.lan> <20111029190938.GA3105@joi.lan> <20111109221009.GD3402@joi.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20111109221009.GD3402-OI9uyE9O0yo@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nouveau-bounces+gcfxn-nouveau=m.gmane.org-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Errors-To: nouveau-bounces+gcfxn-nouveau=m.gmane.org-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org To: Marcin Slusarz Cc: nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Ben Skeggs List-Id: nouveau.vger.kernel.org Le 09/11/2011 23:10, Marcin Slusarz a =E9crit : > For anyone who don't read IRC logs - it turns out it regressed only on = > my box, because I have page flipping disabled (due to page flipping = > being very buggy here, see = > https://bugs.freedesktop.org/show_bug.cgi?id=3D42398), which forces gpu = > context switch on every frame - even with (OpenGL) full screen apps. = > And this patch slows down context switches. So, can we disable xfers = > in ctxprog only when page flipping is enabled? Or is there any other = > option? Marcin = Hmm, it isn't logical yet. To test for performance regression, I = launched the well known context switch test that is glxgears and only = found a performance decrease of 1%. I'll test with pageflip disabled though and see for myself. Anyway, we'll do something about it. I just hope that most cards don't = have this problem. This is clearly an hw regression. Martin