[Mesa-dev] [PATCH 3/3] i965: if DEBUG_OUT_OF_BOUND_CHK is up, check that noise padding for each bo used in batchbuffer is correct

[Rogovin, Kevin]

Hi,

 Just got confirmation that kernel does the syncing required to make sure that pread values are realiable.

-Kevin

-----Original Message-----
From: Rogovin, Kevin 
Sent: Wednesday, December 13, 2017 8:19 AM
To: 'Jason Ekstrand' <jason at jlekstrand.net>
Cc: mesa-dev at lists.freedesktop.org; Lahtinen, Joonas <joonas.lahtinen at intel.com>
Subject: RE: [Mesa-dev] [PATCH 3/3] i965: if DEBUG_OUT_OF_BOUND_CHK is up, check that noise padding for each bo used in batchbuffer is correct

Hi,

> I think you want to do this at the end of submit_batch instead and add 
> a brw_bo_wait_rendering on the batch. Otherwise, your bounds checking is racing with the GPU.

I remember being told that pread has the kernel do the required waiting, however I am not 100% sure of this (which is why I cc'd Joonas to either confirm or deny the assertion). Joonas?
 
-Kevin