A warp or wavefront is a logical unit in GPU kernel scheduling - the largest set of threads within the grid which are (logically) instruction-locked and always synchronized with each other..
I recently read the GK110 white paper, which claims that each SM has 4 warp schedulers, and each with dual Instruction Dispatch Units. On each cycle, each warp scheduler selects an eligible warp to execute instructions for it.
My question is in…
I am currently working on a project in which I am unrolling the last warp of a reduction. I have finished the code above; however, some modifications were done by guessing and I'd like an explanation why. The code I have written is only the function…
I want to implement critical sections in cuda. I read many questions and answers on this subject, and answers often involve atomicCAS and atomicExch.
However, this doesn't work at warp level, since all threads in the warp acquire the same lock after…
Say, dynamic analysis was done on a CUDA program such that certain threads were better off being in the same warp.
For example, let's pretend we have 1024 cuda threads and a warp size of 32. After dynamic analysis we find out that threads 989, 243,…
I have boolean 1D array T[N] controlling the value of shifts as follows:
**a: an array of pointers to n*n matrices in global memory
I want for each matrix a to substruct a shift*Identity to obtain:
a=a-shift*eye(n)
I have:
__device__ bool…
In the online racecheck documentation, the severity level has this description of hazard level WARNING:
An example of this are hazards due to warp level programming that make the assumption that threads are proceeding in groups.
The statement is…
I've got a strange performance inversion on filter kernel with and without branching. Kernel with branching runs ~1.5x faster than the kernel without branching.
Basically I need to sort a bunch of radiance rays then apply interaction kernels. Since…
Given the following simple matrix multiplication kernel
`__global__ void MatrixMulKernel(float* M, float* N, float* P, int
Width)
{
int Row = blockIdx.y*blockDim.y+threadIdx.y;
int Col = blockIdx.x*blockDim.x+threadIdx.x;
if ((Row < Width) &&…
I' m developing with cuda and have an arithmetic problem, which I could implement with or without warp diverengence.
With warp divergence it would look like:
float v1;
float v2;
//calculate values of v1 and v2
if(v2 != 0)
v1 +=…
