This reminds me of a patch Eric wrote that probably fell through the cracks when he migrated jobs:
https://freedesktop.org/patch/26778/ "Free the compiled shader IR after it has been linked" It got an R-B, but seems like it never made it to upstream. I don't know if it still applies to the way things are now though. There might have been a discussion on IRC that concluded that it should be dropped? I don't know. It still has status "New" in patchwork, so seems unlikely. Seems like it should be sort of a big deal, so thought I'd ping it. Regards, Thomas 2015-04-02 11:04 GMT+02:00 Kenneth Graunke <kenn...@whitecape.org>: > While working on NIR's memory allocation model, I realized the GLSL IR > memory model was broken. > > During glCompileShader, we allocate everything out of the > _mesa_glsl_parse_state context, and reparent it to gl_shader at the end. > > During glLinkProgram, we allocate everything out of a temporary context, > then reparent it to the exec_list containing the linked IR. > > But during brw_link_shader - the driver's final opportunity to do > lowering and optimization - we just allocated everything out of the > permanent context given to us by the linker. That memory stayed > forever. > > Notably, passes like brw_fs_channel_expressions cause us to churn the > majority of the code, so we really want to free dead IR here. > > Saves 125MB of memory when replaying a Dota 2 trace on Broadwell. > > Signed-off-by: Kenneth Graunke <kenn...@whitecape.org> > --- > src/mesa/drivers/dri/i965/brw_shader.cpp | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > This depends on my new ralloc_adopt() API, proposed here: > http://lists.freedesktop.org/archives/mesa-dev/2015-March/080763.html > > XXX: need to confirm piglit results (I kicked off tests, but am waiting for > results) > XXX: should probably Cc stable. > > diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp > b/src/mesa/drivers/dri/i965/brw_shader.cpp > index 0dda9bb..b923e54 100644 > --- a/src/mesa/drivers/dri/i965/brw_shader.cpp > +++ b/src/mesa/drivers/dri/i965/brw_shader.cpp > @@ -144,6 +144,11 @@ brw_link_shader(struct gl_context *ctx, struct > gl_shader_program *shProg) > > _mesa_copy_linked_program_data((gl_shader_stage) stage, shProg, prog); > > + /* Temporary memory context for any new IR. */ > + void *mem_ctx = ralloc_context(NULL); > + > + ralloc_adopt(mem_ctx, shader->base.ir); > + > bool progress; > > /* lower_packing_builtins() inserts arithmetic instructions, so it > @@ -249,6 +254,13 @@ brw_link_shader(struct gl_context *ctx, struct > gl_shader_program *shProg) > > _mesa_reference_program(ctx, &prog, NULL); > > + /* Now that we've finished altering the linked IR, reparent any live > IR back > + * to the permanent memory context, and free the temporary one > (discarding any > + * junk we optimized away). > + */ > + reparent_ir(shader->base.ir, shader->base.ir); > + ralloc_free(mem_ctx); > + > if (ctx->_Shader->Flags & GLSL_DUMP) { > fprintf(stderr, "\n"); > fprintf(stderr, "GLSL IR for linked %s program %d:\n", > -- > 2.3.4 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
