[Mesa-dev] [PATCH 0/3] Sweep NIR after linking phase to free held memory

[Danylo Piliaiev]

This patch series is a draft changes to reduce memory usage when
compiling shaders and add utility function to calculate a size of
memory contexts.

The issue I'm attempting to fix described in the bug:
https://bugs.freedesktop.org/show_bug.cgi?id=103274
In short some 32bit games under Wine use a lot of complex shaders
compiling which leads to huge memory usage and sometimes to crashes
due to it.

The changes themselves are trivial but have some price:
After the changes shader with average complexity may link ~3-5% slower.

The savings are huge when compiling a lot of shaders:
In my test case it was around 1mb per shader where the size of nir
after sweep was 20-40kb.

Since the changes slightly slow the compilation and are useful for small
amount of cases I believe that it may be better to introduce new
environment variable to control these sweeps.

I would like to get advice whether this change is desirable and should it
be hidden behind environment variable (if yes suggestions about its name
are welcomed).

Also I wasn't able to test the change in st_link_nir and will welcome
some help with this.

Danylo Piliaiev (3):
  i965: Sweep NIR after linking phase to free held memory
  st: Sweep NIR after linking phase to free held memory
  ralloc: Add ralloc_calc_size to measure memory held by memory contexts

 src/mesa/drivers/dri/i965/brw_link.cpp    |  9 +++++++
 src/mesa/state_tracker/st_glsl_to_nir.cpp |  2 ++
 src/util/ralloc.c                         | 30 +++++++++++++++++++++++
 src/util/ralloc.h                         |  5 ++++
 4 files changed, 46 insertions(+)

-- 
2.17.1