On Tue, May 16, 2017 at 12:21 AM, Thomas Helland <thomashellan...@gmail.com> wrote: > 2017-05-15 21:08 GMT+00:00 Marek Olšák <mar...@gmail.com>: >> On Mon, May 15, 2017 at 10:00 PM, Thomas Helland >> <thomashellan...@gmail.com> wrote: >>> Would this be a win for a game limited by the winsys/buffer handling? >>> I played some Hitman the other day, and noticed my gpu-utilization >>> was hovering at about 80%. Some profiling later and I concluded >>> that one thread was pegged at 100% doing buffer handling work. >>> amdgpu_cs_add_buffer, amdgpu_lookup_buffer, the cso_hash, >>> and a couple other functions related to the winsys where the hottest. >>> Should I expect that to be mitigated by your threaded_gallium work, >>> or by this patch series? If so, I will not delve into that much further =) >> >> amdgpu_cs_add_buffer and amdgpu_lookup_buffer overhead will definitely >> be hidden by threaded gallium. cso_hash will not. >> >> I don't think what you're seeing is related, but I'd be interested in >> a screenshot of sysprof showing what you described. >> >> Marek > > The below dropbox link has two screenshots showing the situation. > The data was collected by attaching perf to the process, > and the report was made with "perf report --hierarchy". > I can collect data with sysprof on Thursday, if you want. > My cpu(FX8320) was hovering at about 50% load at the time, > so with one of eight cores being pegged at 100% that matches > pretty well up with the 24% we're seeing here. > (25% * 50% = 12.5% = 1/8). > As can be seen from the second screenshots the overhead > is quite evently distributed, with no one function being the big offender. > However, what I noticed was amdgpu_cs_add_buffer, > si_set_constant_buffer and amdgpu_lookup_buffer. > I might be completely of track though, so you should > probably take this with the usual tablespoon of salt. > > https://www.dropbox.com/sh/r815zuklfwxy20q/AABrtKkb6Dc4pnW4u5Ul86-Ua?dl=0
I think the problem is that you don't build Mesa with -fno-omit-frame-pointer, so frame-pointer-based profiling doesn't show the total time spent in functions and doesn't show call trees either. To demonstrate what sysprof should look like, this is DrawElements (main app thread): https://people.freedesktop.org/~mareko/sysprof_DrawElements.png This is the basic look at the gallium thread: https://people.freedesktop.org/~mareko/sysprof_gallium_threaded.png And this is the CS ioctl thread. Note that the call tree goes all the way to the kernel driver: https://people.freedesktop.org/~mareko/sysprof_cs_thread.png Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
