bgfx::init allocates 130mb of memory

[metasprite]

bgfx::Init init;
init.type = bgfx::RendererType::OpenGL;
init.vendorId = BGFX_PCI_ID_NONE;
init.resolution.width = 256;
init.resolution.height = 224;
init.platformData.nwh = nwh;
bgfx::init(init);

Windows x64, just cloned 6 days ago. My process skyrockets from 32mb memory usage to 163mb immediately upon the bgfx::init call. My renderer is very lightweight and simple, I don't see the point in allocating so much memory.

I followed the advice from #1715 and changed most BGFX_CONFIG_ values, making them ridiculously low for testing purposes. bgfx::init still allocated 110mb - only 20mb less than before. What is this giant chunk of memory for and how do I reduce it? My application does not need anywhere near that much.

[bkaradzic]

Which BGFX_CONFIG_* defines you changed and to what values?

[metasprite]

Ok, I continued to try to modify the config defines was able to get it to only allocate 75mb on init... better but still seems a bit much. Some of these values are probably too low (because I wanted to test) and I don't know which ones have the most effect. Commented values are the original values:

//( (64<<10)-1)
#ifndef BGFX_CONFIG_MAX_DRAW_CALLS
#	define BGFX_CONFIG_MAX_DRAW_CALLS ( (64<<2)-1)
#endif // BGFX_CONFIG_MAX_DRAW_CALLS

//(1<<10)
#ifndef BGFX_CONFIG_MAX_BLIT_ITEMS
#	define BGFX_CONFIG_MAX_BLIT_ITEMS (1<<4)
#endif // BGFX_CONFIG_MAX_BLIT_ITEMS

//(4<<10)
#ifndef BGFX_CONFIG_MAX_RECT_CACHE
#	define BGFX_CONFIG_MAX_RECT_CACHE (4<<4)
#endif //  BGFX_CONFIG_MAX_RECT_CACHE

// Cannot be configured via compiler options.
#define BGFX_CONFIG_MAX_PROGRAMS (1<<BGFX_CONFIG_SORT_KEY_NUM_BITS_PROGRAM)
BX_STATIC_ASSERT(bx::isPowerOf2(BGFX_CONFIG_MAX_PROGRAMS), "BGFX_CONFIG_MAX_PROGRAMS must be power of 2.");

//256
#ifndef BGFX_CONFIG_MAX_VIEWS
#	define BGFX_CONFIG_MAX_VIEWS 16
#endif // BGFX_CONFIG_MAX_VIEWS
BX_STATIC_ASSERT(bx::isPowerOf2(BGFX_CONFIG_MAX_VIEWS), "BGFX_CONFIG_MAX_VIEWS must be power of 2.");

#define BGFX_CONFIG_MAX_VIEW_NAME_RESERVED 6

//256
#ifndef BGFX_CONFIG_MAX_VIEW_NAME
#	define BGFX_CONFIG_MAX_VIEW_NAME 16
#endif // BGFX_CONFIG_MAX_VIEW_NAME

//64
#ifndef BGFX_CONFIG_MAX_VERTEX_LAYOUTS
#	define BGFX_CONFIG_MAX_VERTEX_LAYOUTS 32
#endif // BGFX_CONFIG_MAX_VERTEX_LAYOUTS

//(4<<10)
#ifndef BGFX_CONFIG_MAX_INDEX_BUFFERS
#	define BGFX_CONFIG_MAX_INDEX_BUFFERS (4<<4)
#endif // BGFX_CONFIG_MAX_INDEX_BUFFERS

//(4<<10)
#ifndef BGFX_CONFIG_MAX_VERTEX_BUFFERS
#	define BGFX_CONFIG_MAX_VERTEX_BUFFERS (4<<4)
#endif // BGFX_CONFIG_MAX_VERTEX_BUFFERS

//(4<<10)
#ifndef BGFX_CONFIG_MAX_DYNAMIC_INDEX_BUFFERS
#	define BGFX_CONFIG_MAX_DYNAMIC_INDEX_BUFFERS (4<<4)
#endif // BGFX_CONFIG_MAX_DYNAMIC_INDEX_BUFFERS

//(4<<10)
#ifndef BGFX_CONFIG_MAX_DYNAMIC_VERTEX_BUFFERS
#	define BGFX_CONFIG_MAX_DYNAMIC_VERTEX_BUFFERS (4<<4)
#endif // BGFX_CONFIG_MAX_DYNAMIC_VERTEX_BUFFERS

//(1<<20)
#ifndef BGFX_CONFIG_DYNAMIC_INDEX_BUFFER_SIZE
#	define BGFX_CONFIG_DYNAMIC_INDEX_BUFFER_SIZE (1<<8)
#endif // BGFX_CONFIG_DYNAMIC_INDEX_BUFFER_SIZE

//(3<<20)
#ifndef BGFX_CONFIG_DYNAMIC_VERTEX_BUFFER_SIZE
#	define BGFX_CONFIG_DYNAMIC_VERTEX_BUFFER_SIZE (3<<8)
#endif // BGFX_CONFIG_DYNAMIC_VERTEX_BUFFER_SIZE

//512
#ifndef BGFX_CONFIG_MAX_SHADERS
#	define BGFX_CONFIG_MAX_SHADERS 32
#endif // BGFX_CONFIG_MAX_FRAGMENT_SHADERS

//4<<10
#ifndef BGFX_CONFIG_MAX_TEXTURES
#	define BGFX_CONFIG_MAX_TEXTURES (4<<8)
#endif // BGFX_CONFIG_MAX_TEXTURES

//16
#ifndef BGFX_CONFIG_MAX_TEXTURE_SAMPLERS
#	define BGFX_CONFIG_MAX_TEXTURE_SAMPLERS 8
#endif // BGFX_CONFIG_MAX_TEXTURE_SAMPLERS

//128
#ifndef BGFX_CONFIG_MAX_FRAME_BUFFERS
#	define BGFX_CONFIG_MAX_FRAME_BUFFERS 16
#endif // BGFX_CONFIG_MAX_FRAME_BUFFERS

//512
#ifndef BGFX_CONFIG_MAX_UNIFORMS
#	define BGFX_CONFIG_MAX_UNIFORMS 32
#endif // BGFX_CONFIG_MAX_UNIFORMS

//256
#ifndef BGFX_CONFIG_MAX_OCCLUSION_QUERIES
#	define BGFX_CONFIG_MAX_OCCLUSION_QUERIES 32
#endif // BGFX_CONFIG_MAX_OCCLUSION_QUERIES

[bkaradzic]

When changing these values don't change shift amount, rather change number.

When you see <<10 it means kilo, or <<20 means mega, etc.

Also check output for info about limits:

../../../src/bgfx.cpp (1649): BGFX Limits:
../../../src/bgfx.cpp (1651): BGFX 	maxDrawCalls                 65535
../../../src/bgfx.cpp (1652): BGFX 	maxBlits                      1024
../../../src/bgfx.cpp (1653): BGFX 	maxTextureSize               16384
../../../src/bgfx.cpp (1654): BGFX 	maxTextureLayers              2048
../../../src/bgfx.cpp (1655): BGFX 	maxViews                       256
../../../src/bgfx.cpp (1656): BGFX 	maxFrameBuffers                128
../../../src/bgfx.cpp (1657): BGFX 	maxFBAttachments                 8
../../../src/bgfx.cpp (1658): BGFX 	maxPrograms                    512
../../../src/bgfx.cpp (1659): BGFX 	maxShaders                     512
../../../src/bgfx.cpp (1660): BGFX 	maxTextures                   4096
../../../src/bgfx.cpp (1661): BGFX 	maxTextureSamplers              16
../../../src/bgfx.cpp (1662): BGFX 	maxComputeBindings              16
../../../src/bgfx.cpp (1663): BGFX 	maxVertexLayouts                64
../../../src/bgfx.cpp (1664): BGFX 	maxVertexStreams                 4
../../../src/bgfx.cpp (1665): BGFX 	maxIndexBuffers               4096
../../../src/bgfx.cpp (1666): BGFX 	maxVertexBuffers              4096
../../../src/bgfx.cpp (1667): BGFX 	maxDynamicIndexBuffers        4096
../../../src/bgfx.cpp (1668): BGFX 	maxDynamicVertexBuffers       4096
../../../src/bgfx.cpp (1669): BGFX 	maxUniforms                    512
../../../src/bgfx.cpp (1670): BGFX 	maxOcclusionQueries            256
../../../src/bgfx.cpp (1671): BGFX 	maxEncoders                      8
../../../src/bgfx.cpp (1672): BGFX 	minResourceCbSize            65536
../../../src/bgfx.cpp (1673): BGFX 	transientVbSize            6291456
../../../src/bgfx.cpp (1674): BGFX 	transientIbSize            2097152

Try following:

# define BGFX_CONFIG_MAX_DRAW_CALLS 1024

# define BGFX_CONFIG_MAX_BLIT_ITEMS 256

# define BGFX_CONFIG_TRANSIENT_VERTEX_BUFFER_SIZE (64<<10)

# define BGFX_CONFIG_TRANSIENT_INDEX_BUFFER_SIZE (64<<10)

[metasprite]

# define BGFX_CONFIG_MAX_DRAW_CALLS 1024

# define BGFX_CONFIG_MAX_BLIT_ITEMS 256

# define BGFX_CONFIG_TRANSIENT_VERTEX_BUFFER_SIZE (64<<10)

# define BGFX_CONFIG_TRANSIENT_INDEX_BUFFER_SIZE (64<<10)

Out of those, reducing max draw calls caused by far the biggest change. I am not drawing very many things so I will keep it at 256 for now. Thanks. Edit: or 1024 since it uses the same amount of memory...

[bkaradzic]

Yeah, idea with these settings is to adjust them once you need to ship the game/app. I would suggest to keep them 2x of what you actually need for development, and then reduce once you're ready to ship.

[bkaradzic]

Also mask off all features you're not using:

bgfx/include/bgfx/bgfx.h

Line 665 in 84fcbcd

uint64_t capabilities; //!< Capabilities initialization mask (default: UINT64_MAX).