On 4/2/25 10:52, Jaco Kroon wrote: > Hi, > > On 2025/04/02 10:18, Miklos Szeredi wrote: >> On Wed, 2 Apr 2025 at 09:55, Jaco Kroon <jaco@xxxxxxxxx> wrote: >>> Hi, >>> >>> I can definitely build on that, thank you. >>> >>> What's the advantage of kvmalloc over folio's here, why should it be >>> preferred? >> It offers the best of both worlds: first tries plain malloc (which >> just does a folio alloc internally for size > PAGE_SIZE) and if that >> fails, falls back to vmalloc, which should always succeed since it >> uses order 0 pages. > > So basically assigns the space, but doesn't commit physical pages for > the allocation, meaning first access will cause a page fault, and single > page allocation at that point in time? Or is it merely the fact that > vmalloc may return a virtual contiguous block that's not physically > contiguous? Yes vmalloc return buffers might not be physically contiguous - not suitable for hardware DMA. And AFAIK it is also a blocking allocation. Bernd
