[Mesa-dev] [PATCH 00/15] GLSL memory allocation rework for faster compilation

Tapani Pälli tapani.palli at intel.com
Mon Oct 10 05:58:14 UTC 2016



On 10/08/2016 06:58 PM, Jason Ekstrand wrote:
> FYI, we use ralloc for a lot more than just the glsl compiler so the
> first few changes make me a bit nervous.  There was someone working on
> making our driver more I undefined-memory-friendly but I don't know what
> happened to those patches.

There's bunch of patches like that in this series:
https://lists.freedesktop.org/archives/mesa-dev/2016-June/120445.html

it looks like it just never landed as would have required more testing 
on misc drivers?

>
> On Oct 8, 2016 3:58 AM, "Marek Olšák" <maraeo at gmail.com
> <mailto:maraeo at gmail.com>> wrote:
>
>     Hi,
>
>     This patch series reduces the number of malloc calls in the GLSL
>     compiler by 63%. That leads to better compile times and less heap
>     thrashing.
>
>     It's done by switching memory allocations in the GLSL compiler to my
>     new linear allocator that allocates out of a fixed-sized buffer with
>     a monotonically increasing offset. If more buffers are needed, it
>     chains them.
>
>     The new allocator is used in all places where short-lived allocations
>     are used with a high number of malloc calls. The series also contains
>     other improvements not related to the new allocator that also improve
>     compile times. The results are below.
>
>     I tested my shader-db with shaders only being compiled to TGSI.
>     (noop gallium driver)
>
>
>     master + libc's malloc:
>
>      real   0m54.182s
>      user   3m33.640s
>      sys    0m0.620s
>      maxmem 275 MB
>
>
>     master + jemalloc preloaded:
>
>      real   0m45.044s
>      user   2m56.356s
>      sys    0m1.652s
>      maxmem 284 MB
>
>
>     the series + libc's malloc:
>
>      real   0m46.221s
>      user   3m2.080s
>      sys    0m0.544s
>      maxmem 270 MB
>
>
>     the series + jemalloc preloaded:
>
>      real   0m40.729s
>      user   2m39.564s
>      sys    0m1.232s
>      maxmem 284 MB
>
>
>     The series without jemalloc almost caught up with jemalloc + master.
>     However, jemalloc also benefits.
>
>     Current Mesa needs 54.182s and it drops to 40.729s with my series and
>     jemalloc. The total change in compile time is -25% if we incorporate
>     both. Without jemalloc, the difference is only -14.7%.
>
>     With radeonsi, the improvement is approx. slightly more than 1/2 of that
>     (if you add the LLVM time). However, radeonsi also has asynchronous
>     shader compilation hiding LLVM overhead in some cases, so it depends.
>
>     Drivers with faster compiler backends will benefit more than radeonsi,
>     but will probably not reach -25% or -14.7% (except softpipe, which uses
>     TGSI as-is).
>
>     The memory usage looks reasonable in all tested cases.
>
>     Note: One of the first patches moves memset from ralloc to rzalloc.
>     I tested and fixed the GLSL source -> TGSI path, but other codepaths
>     may break, and you need to use valgrind to find all uninitialized
>     variables that relied on ralloc doing memset (if there are any).
>
>     You can also find it here:
>     https://cgit.freedesktop.org/~mareko/mesa/log/?h=glsl-alloc-rework
>     <https://cgit.freedesktop.org/~mareko/mesa/log/?h=glsl-alloc-rework>
>
>     Please review.
>
>      src/compiler/glsl/ast.h                             |   4 +-
>      src/compiler/glsl/ast_to_hir.cpp                    |   4 +-
>      src/compiler/glsl/ast_type.cpp                      |  13 ++-
>      src/compiler/glsl/glcpp/glcpp-lex.l                 |   2 +-
>      src/compiler/glsl/glcpp/glcpp-parse.y               | 203
>     +++++++++++++++++---------------------
>      src/compiler/glsl/glcpp/glcpp.h                     |   1 +
>      src/compiler/glsl/glsl_lexer.ll                     |  16 +--
>      src/compiler/glsl/glsl_parser.yy                    | 202
>     +++++++++++++++++++-------------------
>      src/compiler/glsl/glsl_parser_extras.cpp            |   6 +-
>      src/compiler/glsl/glsl_parser_extras.h              |   4 +-
>      src/compiler/glsl/glsl_symbol_table.cpp             |  19 ++--
>      src/compiler/glsl/glsl_symbol_table.h               |   1 +
>      src/compiler/glsl/ir.cpp                            |   4 +
>      src/compiler/glsl/ir.h                              |  13 ++-
>      src/compiler/glsl/link_uniform_blocks.cpp           |   2 +-
>      src/compiler/glsl/list.h                            |   2 +-
>      src/compiler/glsl/lower_packed_varyings.cpp         |   8 +-
>      src/compiler/glsl/opt_constant_propagation.cpp      |  14 ++-
>      src/compiler/glsl/opt_copy_propagation.cpp          |   7 +-
>      src/compiler/glsl/opt_copy_propagation_elements.cpp |  19 ++--
>      src/compiler/glsl/opt_dead_code_local.cpp           |  12 ++-
>      src/compiler/glsl_types.cpp                         |  38 +------
>      src/compiler/glsl_types.h                           |   6 +-
>      src/compiler/nir/nir.c                              |   8 +-
>      src/compiler/spirv/vtn_variables.c                  |   3 +-
>      src/gallium/drivers/freedreno/ir3/ir3.c             |   2 +-
>      src/gallium/drivers/vc4/vc4_cl.c                    |   2 +-
>      src/gallium/drivers/vc4/vc4_program.c               |   2 +-
>      src/gallium/drivers/vc4/vc4_simulator.c             |   5 +-
>      src/mesa/drivers/dri/i965/brw_state_batch.c         |   5 +-
>      src/util/ralloc.c                                   | 392
>     ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
>      src/util/ralloc.h                                   |  93
>     ++++++++++++++++--
>      32 files changed, 782 insertions(+), 330 deletions(-)
>
>     Marek
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>
>
>
>
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