2017-05-16 1:05 GMT+02:00 Marek Olšák <mar...@gmail.com>: > 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
Hmm... It might be that I'm somehow misrepresenting the data. I'm quite confident I built with no-omit-frame-pointer though, as I specifically spent a good amount of time figuring out how to add the correct compile flags to the build without enabling other debugging functions. But I might have messed up something. I'll look into this a bit closer when I find the time, but that likely won't be until Thursday as the very earliest. Thanks for the help, it's always appreciated! _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
