On 7/12/23 18:24, Felix Kuehling wrote: > Allocations in the heap and stack tend to be small, with several > allocations sharing the same page. Sharing the same page for different > allocations with different access patterns leads to thrashing when we > migrate data back and forth on GPU and CPU access. To avoid this we > disable HMM migrations for head and stack VMAs. Wonder how well does it really work in practice? AFAIK "heaps" (malloc()) today uses various arenas obtained by mmap() and not a single brk() managed space anymore? And programs might be multithreaded, thus have multiple stacks, while vma_is_stack() will recognize only the initial one... Vlastimil > Regards, > Felix > > > Am 2023-07-12 um 10:42 schrieb Christoph Hellwig: >> On Wed, Jul 12, 2023 at 10:38:29PM +0800, Kefeng Wang wrote: >>> Use the helpers to simplify code. >> Nothing against your addition of a helper, but a GPU driver really >> should have no business even looking at this information.. >> >> >
