Work-groups' number

[Altera_Forum]

Hi everyone, 

I would like to say how I can set the number of work groups. I know the attribute "reqd_work_group_size(X,Y,Z)" allows to establish the number of W-I inside a work group (W-G's dimension) in three dimensions but it is not clear to me how to decide the number of these W-G. Could you help me? Thanks for your help

[Altera_Forum]

The local size (number of work-items per work-group) and global size (total number of work-items) are both set in the host code and passed as arguments to clEnqueueNDRangeKernel(). The number of work-groups per dimension is equal to global size per dimension divided by local size per dimension. If you are using reqd_work_group_size() in the kernel, the local size you pass to clEnqueueNDRangeKernel() in the host code MUST match the numbers you pass to reqd_work_group_size() or else the kernel launch will fail.

[Altera_Forum]

Ok thanks. Then the numbers in the attribute "reqd_work_group_size" represent the local size (in three dimensions) not the global size, is it correct? Thanks.

[Altera_Forum]

--- Quote Start ---  Ok thanks. Then the numbers in the attribute "reqd_work_group_size" represent the local size (in three dimensions) not the global size, is it correct? Thanks.  --- Quote End ---   Yes, it represents the local size (also called work-group size).

[Altera_Forum]

Perfect. Thanks yor your help