On 26 June 2017 at 19:10, zhoucm1 <david1.zhou at amd.com> wrote: > > > On 2017å¹´06æ??26æ?¥ 03:48, Dave Airlie wrote: >>> >>> Do you not use bo list at all in mesa? radv as well? >> >> Currently radv is creating a bo list per command submission. radv does >> not use an offload thread to do command submission, as it seems pretty >> un-vulkan to use a thread for the queue submission thread the game >> uses. >> >> I have considered investigating this, but with vulkan it's probably >> optimising for the single threaded case which isn't where apps should >> really be. >> >> At the moment we regenerate the bo list on every CS ioctl, we probably >> can do a lot better, I know Bas has looked into this area a bit more >> than I. > > Thanks Dave for inputting. > > Could I ask more about radv? How does radv make bo list for every cs ioctl? > Adding filter in every operation, any related bo will be add to bo list > during make command submission? When we create command buffers we add each bo to a list for it, but we don't call the kernel ioctl. When we get a QueueSubmit, we usually submit two IBs to the kernel, one with some cache flushes and one with the main IB in it, however as we have to give the kernel one bo list we have to combine the two lists (even if the cache flush list only has one ib in it, itself), so we can't call create bo list early, we have to do it just before command submission. However I don't think we've had any problems with this being our slow path yet, but this may change in the future. Dave.
