On Mon, 16 Sep 2019 17:20:28 -0500 Rob Herring <robh@xxxxxxxxxx> wrote: > On Fri, Sep 13, 2019 at 6:17 AM Boris Brezillon > <boris.brezillon@xxxxxxxxxxxxx> wrote: > > > > The READ/WRITE flags are particularly useful if we want to avoid > > serialization of jobs that read from the same BO but never write to it. > > Any data on performance differences? Unfortunately no. When I initially added support for BO flags I thought it would fix a regression I had on one glmark2 test (ideas), but the problem ended up being something completely different (overhead of calling ioctl(WAIT_BO) on already idle BOs). I just ran glmark2 again, and there doesn't seem to be a noticeable improvement with those 2 patches applied (and mesa patched to use the new flags). This being said, the improvement is likely to be workload dependent, so I wouldn't consider these patches as useless, but I'm fine putting them on hold until we see a real need. Maybe Steven has some real use cases that could help outline the benefit of these patches. > > > The NO_IMPLICIT_FENCE might be useful when the user knows the BO is > > shared but jobs are using different portions of the buffer. > > Why don't we add this when it is useful rather than might be? I don't have a need for that one yet, but etanviv has it in place so I thought I'd add both at the same time. Note that it could help us reduce the number of fence returned by panfrost_job_dependency(), but I'm not sure it makes a difference in terms of perfs. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
