On 6 June 2016 at 16:46, Bas Nieuwenhuizen <b...@basnieuwenhuizen.nl> wrote: > On Mon, Jun 6, 2016 at 5:14 PM, Nicolai Hähnle <nhaeh...@gmail.com> wrote: >> On 06.06.2016 00:28, Bas Nieuwenhuizen wrote: >>> >>> This fixes a problem with the CE preamble and restoring only stuff in the >>> preamble when needed. >>> >>> To illustrate suppose we have two graphics IB's 1 and 2, which are >>> submitted in >>> that order. Furthermore suppose IB 1 does not use CE ram, but IB 2 does, >>> and we >>> have a context switch at the start of IB 1, but not between IB 1 and IB 2. >>> >>> The old code put the CE RAM loads in the preamble of IB 2. As the preamble >>> of >>> IB 1 does not have the loads and the preamble of IB 2 does not get >>> executed, the >>> old values are not load into CE RAM. >>> >>> Fix this by always restoring the entire CE RAM. >> >> >> Nice catch! >> >> Have you considered restoring from the desc->buffers instead? The >> double-dump seems a bit redundant. But maybe it's easier this way... >> >> Also, do we really need to dump the entire CE RAM? After initializing the >> descriptor sets, we should know exactly how much we need... > > We can do both. > > However, wrt using the desc->buffers, note that this results in 21 > loads (and adding potentially multiple buffers to the CS bo list) > while the current approach is 1 load > and 1 store. Furthermore the CE is <= 15% busy in pretty much all > games I tried, as measured by polling CP_STAT.CE_BUSY. As such I > haven't really considered optimizing this GPU side and I'm not really > sure if it is worth it in this case to do a bit more work on the CPU > to avoid some work on the GPU. > > Though I'm probably overthinking this given how small an impact the > whole CE stuff had on performance and we're now talking about a per IB > cost instead of per draw. > Gents, double-checking: The patch has been superseded (with 54f755fa0fda14c578022767bcef2f27b2e89707?), correct ?
Thanks Emil _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
