Hi Lucas, 2017-01-30 12:48 GMT+01:00 Lucas Stach <l.stach@xxxxxxxxxxxxxx>: > Am Mittwoch, den 18.01.2017, 12:25 +0100 schrieb Lucas Stach: >> Hi all, >> >> the following patches introduce a cmduf suballocator in the Etnaviv >> kernel driver, which has the following benefits: >> >> 1. Allocating and freeing a CMA buffer for each user command submission >> is taking a big toll on the CPU, as CMA is not exactly low overhead. >> By suballocating a single buffer we avoid all this overhead. >> >> 2. Less TLB flushes on MMUv2. Each time a new buffer gets mapped into >> the GPU address space on MMUv2 the TLBs need to be flushed. Mapping >> the suballocated area once allows to skip the TLB flushes (at least >> as long as userspace re-uses existing buffers). >> >> 3. No workarounds for GC3000 required anymore. The FE TLB flush on >> GC3000 doesn't work reliably, which required us to map the cmdbufs >> into the GPU address space at specific positions, which also isn't >> guaranteed to work if the address space is already crowded. Having >> a single static area for the cmdbufs side-steps the erratum completely. >> >> If I can get reviews and/or enough testing, I would like to include this >> code in kernel 4.11. > > If this helps in testing this change, I have pushed my queue out into my > public git repo at: > > https://git.pengutronix.de/git/lst/linux drm-etnaviv-next > > The branch is based on v4.10-rc1, but is trivial to rebase onto > something more recent. > Will have a look at it later the day. greets -- Christian Gmeiner, MSc https://www.youtube.com/user/AloryOFFICIAL https://soundcloud.com/christian-gmeiner _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
