Mesa vs RocM opencl perf differences
Dr. David Alan Gilbert
dave at treblig.org
Sun May 7 21:03:03 UTC 2023
Hi,
I'm looking for suggestions on how to diagnose a large, confused,
performance difference between Mesa and RocM.
The code:
https://github.com/penguin42/vhs-teletext/blob/vectorised/teletext/vbi/patternopencl.py
is pyopencl driven and part of a large program.
(Running it is pretty easy, but you do need a chunk of data
which is normally collected off received video; I could provide a sample
privately)
There are three kernels in there
correlate, minerr1, minerr2
that are chained together.
and it runs multiple _processes_ each running all the kernels.
On one set of data (tapedg004) which mostly uses a smaller data
set, Mesa beats RocM, on the bigger data set, the simple correlate
kernel is about 50% slower on mesa:
64k dataset:
kernel: correlate | minerr1 | minerr2
MESA 2.3ms 0.84ms * 0.15ms *
ROCM 1.1ms * 0.88ms 0.18ms
8k dataset:
kernel: correlate | minerr1 | minerr2
MESA 0.127ms * 0.078ms * 0.059ms *
ROCM 0.166ms 0.120ms 0.090ms
So generally the minerr kernel is faster on Mesa
(sometimes a lot) but in the large data case
the correlate kernel is more than twice as slow.
What surprises me is that the correlate kernel is the
simpler of the kernels in my mind!
Host is Fedora 38, on Ryzen 3950X; clinfo from mesa below.
All pointers welcome.
Dave
Clinfo from Mesa
Number of platforms 2
Platform Name Clover
Platform Vendor Mesa
Platform Version OpenCL 1.1 Mesa 23.0.3
Platform Profile FULL_PROFILE
Platform Extensions cl_khr_icd
Platform Extensions function suffix MESA
Platform Name rusticl
Platform Vendor Mesa/X.org
Platform Version OpenCL 3.0
Platform Profile FULL_PROFILE
Platform Extensions cl_khr_icd
Platform Extensions with Version cl_khr_icd 0x
400000 (1.0.0)
Platform Numeric Version 0xc00000 (3.0.0)
Platform Extensions function suffix MESA
Platform Host timer resolution 0ns
Platform Name Clover
Number of devices 1
Device Name AMD Radeon RX 550 / 550 Series (polaris12, LLVM 16.0.1, DRM 3.49, 6
.2.14-300.fc38.x86_64)
Device Vendor AMD
Device Vendor ID 0x1002
Device Version OpenCL 1.1 Mesa 23.0.3
Device Numeric Version 0x401000 (1.1.0)
Driver Version 23.0.3
Device OpenCL C Version OpenCL C 1.1
Device Type GPU
Device Profile FULL_PROFILE
Device Available Yes
Compiler Available Yes
Max compute units 8
Max clock frequency 1206MHz
Max work item dimensions 3
Max work item sizes 256x256x256
Max work group size 256
Preferred work group size multiple (kernel) 64
Preferred / native vector sizes
char 16 / 16
short 8 / 8
int 4 / 4
long 2 / 2
half 0 / 0 (n/a)
float 4 / 4
double 2 / 2 (cl_khr_fp64)
Half-precision Floating-point support (n/a)
Single-precision Floating-point support (core)
Denormals No
Infinity and NANs Yes
Round to nearest Yes
Round to zero No
Round to infinity No
IEEE754-2008 fused multiply-add No
Support is emulated in software No
Correctly-rounded divide and sqrt operations No
Double-precision Floating-point support (cl_khr_fp64)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero Yes
Round to infinity Yes
IEEE754-2008 fused multiply-add Yes
Support is emulated in software No
Address bits 64, Little-Endian
Global memory size 2147483648 (2GiB)
Error Correction support No
Max memory allocation 536870912 (512MiB)
Unified memory for Host and Device No
Minimum alignment for any data type 128 bytes
Alignment of base address 32768 bits (4096 bytes)
Global Memory cache type None
Image support No
Local memory type Local
Local memory size 65536 (64KiB)
Max number of constant args 16
Max constant buffer size 67108864 (64MiB)
Max size of kernel argument 1024
Queue properties
Out-of-order execution No
Profiling Yes
Profiling timer resolution 0ns
Execution capabilities
Run OpenCL kernels Yes
Run native kernels No
ILs with version SPIR-V 0x
400000 (1.0.0)
Built-in kernels with version (n/a)
Device Extensions cl_khr_byte_addressable_store cl_khr_global_int32_base_atomics cl_k
hr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_int64_bas
e_atomics cl_khr_int64_extended_atomics cl_khr_fp64 cl_khr_extended_versioning
Device Extensions with Version cl_khr_byte_addressable_store 0x
400000 (1.0.0)
cl_khr_global_int32_base_atomics 0x
400000 (1.0.0)
cl_khr_global_int32_extended_atomics 0x
400000 (1.0.0)
cl_khr_local_int32_base_atomics 0x
400000 (1.0.0)
cl_khr_local_int32_extended_atomics 0x
400000 (1.0.0)
cl_khr_int64_base_atomics 0x
400000 (1.0.0)
cl_khr_int64_extended_atomics 0x
400000 (1.0.0)
cl_khr_fp64 0x
400000 (1.0.0)
cl_khr_extended_versioning 0x
400000 (1.0.0)
Platform Name rusticl
Number of devices 0
NULL platform behavior
clGetPlatformInfo(NULL, CL_PLATFORM_NAME, ...) Clover
clGetDeviceIDs(NULL, CL_DEVICE_TYPE_ALL, ...) Success [MESA]
clCreateContext(NULL, ...) [default] Success [MESA]
clCreateContext(NULL, ...) [other]
clCreateContextFromType(NULL, CL_DEVICE_TYPE_DEFAULT) Success (1)
Platform Name Clover
Device Name AMD Radeon RX 550 / 550 Series (polaris12, LLVM 16.0.1, DRM 3.49, 6
.2.14-300.fc38.x86_64)
clCreateContextFromType(NULL, CL_DEVICE_TYPE_CPU) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_GPU) Success (1)
Platform Name Clover
Device Name AMD Radeon RX 550 / 550 Series (polaris12, LLVM 16.0.1, DRM 3.49, 6
.2.14-300.fc38.x86_64)
clCreateContextFromType(NULL, CL_DEVICE_TYPE_ACCELERATOR) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_CUSTOM) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_ALL) Success (1)
Platform Name Clover
Device Name AMD Radeon RX 550 / 550 Series (polaris12, LLVM 16.0.1, DRM 3.49, 6
.2.14-300.fc38.x86_64)
ICD loader properties
ICD loader Name OpenCL ICD Loader
ICD loader Vendor OCL Icd free software
ICD loader Version 2.3.1
ICD loader Profile OpenCL 3.0
--
-----Open up your eyes, open up your mind, open up your code -------
/ Dr. David Alan Gilbert | Running GNU/Linux | Happy \
\ dave @ treblig.org | | In Hex /
\ _________________________|_____ http://www.treblig.org |_______/
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