Re: [PATCH 08/16] nouveau/hmm: fault one page at a time

On Fri, Jun 19, 2020 at 02:56:41PM -0700, Ralph Campbell wrote:

The SVM page fault handler groups faults into a range of contiguous virtual addresses and requests hmm_range_fault() to populate and return the page frame number of system memory mapped by the CPU. In preparation for supporting large pages to be mapped by the GPU, process faults one page at a time. In addition, use the hmm_range default_flags to fix a corner case where the input hmm_pfns array is not reinitialized after hmm_range_fault() returns -EBUSY and must be called again.

Are you sure? hmm_range_fault is pretty expensive per call..

Jason