[Dri-devel] Re: [Xpert]XvShmPutImage on r128 eating too much CPU, round 4

[Mark V. <mvo...@nv...>]

On Tue, 7 May 2002, Peter Surda wrote:

> Hi!
> 
> Preface for those who don't remember: playing videos on r128 with
> XvShmPutImage used to take a lot of CPU time, about 25% for DVD, inside
> SYSTEM. The cause was found to be slow videoram and was solved by using
> DRI's
> DMA functions. Suddenly, several months later, roughly the same amount
> of CPU
> again started to be consumed, this time in userspace though, even if DRI
> is
> enabled. If DRI is disabled, it is even worse: CPU time is eaten both in
> SYSTEM and USER, consuming a total of about 50% CPU while basically
> doing
> nothing.
> 
> I have yet another idea what could be causing this.
> 
> As Volodya said, calling XvShmPutImage doesn't actually put the stuff on
> the
> screen, it just queues it and returns. A client application (in my case
> SDL
> and Mplayer's vo_xv) then calls XSync (or XFlush) immediately
> afterwards. I
> assume XSync does a busy loop, which "eats CPU time". 

   No.  XSync goes to sleep until the X-server replies.



				Mark.