Hi,
On 13.2.2020 20.44, Dylan Baker wrote:
I actually spent a bunch of time toying with PGO a couple of years ago. I got
the guidance all working and was able to train it, but what we found was that it
made the specific workloads we threw at it much faster, but it made every real
world use case I tried (playing a game, running piglit, gnome) slower, often
significantly so.
The hard part is not setting up pgo, it's getting the right training data.
Do you still remember what exact use-cases were used for training, and
what exact cases suffered worst as a result? Did you for example
profile also X server, and (some) X and Wayland compositor during
the application profiling?
Also, did you use normal FDO (instrumented code) or AutoFDO (profiling)
to gather the profiling data? I'm wondering whether AutoFDO could be
done so that you install Mesa to the system, profile the whole system,
and just filter out non-Mesa profiling data when applying the
information to the new build...
- Eero
Dylan
Quoting Marek Olšák (2020-02-13 10:30:46)
[Forked from the other thread]
Guys, we could run some simple tests similar to piglit/drawoverhead as the last
step of the pgo=generate build. Tests like that should exercise the most common
codepaths in drivers. We could add subtests that we care about the most.
Marek
On Thu., Feb. 13, 2020, 13:16 Dylan Baker, wrote:
meson has buildtins for both of these, -Db_lto=true turns on lto, for pgo
you
would run:
meson build -Db_pgo=generate
ninja -C build
meson configure build -Db_pgo=use
ninja -C build
Quoting Marek Olšák (2020-02-12 10:46:12)
> How do you enable LTO+PGO? Is it something we could enable by default for
> release builds?
>
> Marek
>
> On Wed, Feb 12, 2020 at 1:56 AM Dieter Nützel
wrote:
>
> Hello Gert,
>
> your merge 'broke' LTO and then later on PGO compilation/linking.
>
> I do generally compiling with '-Dgallium-drivers=
r600,radeonsi,swrast'
> for testing radeonsi and (your) r600 work. ;-)
>
> After your merge I get several warnings in 'addrlib' with LTO and
even a
> compiler error (gcc (SUSE Linux) 9.2.1 20200128).
>
> I had to disable 'r600' ('swrast' is needed for 'nine') to get a
working
> LTO and even better PGO radeonsi driver.
> I'm preparing GREAT LTO+PGO (the later is the greater) numbers over
the
> last 2 months. I'll send my results later, today.
>
> Summary
> radeonsi is ~40% smaller and 16-20% faster with PGO (!!!).
>
> Honza and the GCC people (Intel's ICC folks) do GREAT things.
> 'glmark2' numbers are better then 'vkmark'. (Hello, Marek.).
>
> Need some sleep.
>
> See my log, below.
>
> Greetings and GREAT work!
>
> -Dieter
>
> Am 09.02.2020 15:46, schrieb Gert Wollny:
> > Am Donnerstag, den 23.01.2020, 20:31 +0100 schrieb Gert Wollny:
> >> has anybody any objections if I merge the r600/NIR code?
> >> Without explicitely setting the debug flag it doesn't change a
> >> thing, but it would be better to continue developing in-tree.
> > Okay, if nobody objects, I'll merge it Monday evening.
> >
> > Best,
> > Gert
>
> [1425/1433] Linking target src/gallium/targets/dri/libgallium_dri.so.
> FAILED: src/gallium/targets/dri/libgallium_dri.so
> c++ -o src/gallium/targets/dri/libgallium_dri.so
> 'src/gallium/targets/dri/8381c20@@gallium_dri@sha/target.c.o' -flto
> -fprofile-generate -Wl,--as-needed -Wl,--no-undefined -Wl,-O1 -shared
> -fPIC -Wl,--start-group -Wl,-soname,libgallium_dri.so
> src/mesa/libmesa_gallium.a src/mesa/libmesa_common.a
> src/compiler/glsl/libglsl.a src/compiler/glsl/glcpp/libglcpp.a
> src/util/libmesa_util.a src/util/format/libmesa_format.a
> src/compiler/nir/libnir.a src/compiler/libcompiler.a
> src/mesa/libmesa_sse41.a src/mesa/drivers/dri/common/libdricommon.a
> src/mesa/drivers/dri/common/libmegadriver_stub.a
> src/gallium/state_trackers/dri/libdri.a
> src/gallium/auxiliary/libgalliumvl.a src/gallium/auxiliary/
libgallium.a
> src/mapi/shared-glapi/libglapi.so.0.0.0
> src/gallium/auxiliary/pipe-loader/libpipe_loader_static.a
> src/loader/libloader.a src/util/libxmlconfig.a
> src/gallium/winsys/sw/null/libws_null.a
> src/gallium/winsys/sw/wrapper/libwsw.a
> src/gallium/winsys/sw/dri/libswdri.a
> src/gallium/winsys/sw/kms-dri/libswkmsdri.a
> src/gallium/drivers/llvmpipe/libllvmpipe.a
> src/gallium/drivers/softpipe/libsoftpipe.a
> src/gallium/drivers/r600/libr600.a
>
