On Thu, 2015-09-03 at 13:52 +0300, Tapani Pälli wrote: > > On 09/03/2015 01:40 PM, Samuel Iglesias Gonsálvez wrote: > > > > > > On 03/09/15 12:30, Tapani Pälli wrote: > >> Hi; > >> > >> On 07/23/2015 09:42 AM, Samuel Iglesias Gonsalvez wrote: > >>> v2: > >>> - Add tessellation shader constants assignment > >>> > >>> Signed-off-by: Samuel Iglesias Gonsalvez <sigles...@igalia.com> > >>> --- > >>> src/mesa/drivers/dri/i965/brw_context.c | 12 ++++++++++++ > >>> 1 file changed, 12 insertions(+) > >>> > >>> diff --git a/src/mesa/drivers/dri/i965/brw_context.c > >>> b/src/mesa/drivers/dri/i965/brw_context.c > >>> index b08a53b..a5c7b91 100644 > >>> --- a/src/mesa/drivers/dri/i965/brw_context.c > >>> +++ b/src/mesa/drivers/dri/i965/brw_context.c > >>> @@ -551,6 +551,18 @@ brw_initialize_context_constants(struct > >>> brw_context *brw) > >>> ctx->Const.TextureBufferOffsetAlignment = 16; > >>> ctx->Const.MaxTextureBufferSize = 128 * 1024 * 1024; > >>> > >>> + /* FIXME: Tessellation stages are not yet supported in i965, so > >>> + * MaxCombinedShaderStorageBlocks doesn't take them into account. > >>> + */ > >>> + ctx->Const.Program[MESA_SHADER_VERTEX].MaxShaderStorageBlocks = 12; > >>> + ctx->Const.Program[MESA_SHADER_GEOMETRY].MaxShaderStorageBlocks = 12; > >>> + ctx->Const.Program[MESA_SHADER_TESS_EVAL].MaxShaderStorageBlocks = 0; > >>> + ctx->Const.Program[MESA_SHADER_TESS_CTRL].MaxShaderStorageBlocks = 0; > >>> + ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxShaderStorageBlocks = 12; > >>> + ctx->Const.Program[MESA_SHADER_COMPUTE].MaxShaderStorageBlocks = 12; > >>> + ctx->Const.MaxCombinedShaderStorageBlocks = 12 * 3; > >>> + ctx->Const.MaxShaderStorageBufferBindings = 48; > >> > >> I think there is something funny with MaxShaderStorageBufferBindings > >> value calculation. Commit 28ef0f83 adds 12 to it and then this commit > >> overwrites it as 48. Without compute shaders I guess this value should > >> be 48 - 12? > >> > >> I guess earlier '+12' should be removed and this part should be modified > >> to calculate based on what is supported. For me '48 -12' fixes a few > >> crashes I'm getting with > >> "igalia/wip/siglesias/ARB_shader_storage_buffer_object-v4.3" branch I've > >> used for some testing. > >> > > > > I see. We are going to review the MaxShaderStorageBufferBindings > > calculation, thanks for the report and the ideas. > > > > Can you share with us the tests that crashed because of this? You can > > send them privately to me, if needed. > > These are some Piglit tests that use buffer objects. Crash happens at > _mesa_free_buffer_objects(), it's not quite clear yet to me why (maybe > memory gets trashed) but I bisected it to this commit changing > MaxShaderStorageBufferBindings. For example > 'arb_framebuffer_no_attachments-atomic' segfaults when destroying the > context and calling _mesa_free_buffer_objects(). > > Here's example backtrace: > (gdb) bt > #0 0x00007ffff3dae830 in pthread_mutex_lock () from /lib64/libpthread.so.0 > #1 0x00007ffff1da8681 in mtx_lock (mtx=0xffffffffffffffff) at > ../../include/c11/threads_posix.h:192 > #2 _mesa_reference_buffer_object_ (ctx=0x7ffff7fd0040, > ptr=0x7ffff7ff13d0, bufObj=0x0) at main/bufferobj.c:450 > #3 0x00007ffff1da9173 in _mesa_reference_buffer_object (bufObj=0x0, > ptr=<optimized out>, ctx=0x7ffff7fd0040) at main/bufferobj.h:123 > #4 _mesa_free_buffer_objects (ctx=ctx@entry=0x7ffff7fd0040) at > main/bufferobj.c:907 > #5 0x00007ffff1db553b in _mesa_free_context_data > (ctx=ctx@entry=0x7ffff7fd0040) at main/context.c:1342 > #6 0x00007ffff2077a3e in intelDestroyContext (driContextPriv=0x6392f0) > at brw_context.c:996 > > it crashes because 'oldObj' in _mesa_reference_buffer_object_ points to > 0xffffffffffffffff.
Thanks for reporting this, the problem with the crash is that there is a mismatch between the number of bindings used by the driver and the maximum declared by Mesa, this was actually a silly mistake we introduced after updating some of our code during reviews. To fix this you need to set MAX_SHADER_STORAGE_BUFFERS in src/mesa/main/config.h to 15 (instead of the current value of 7, the issue comes from 7*6 = 42 < 48). Samuel is going to look into the +12 issue you also mentioned. Iago _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
