Messages in this thread | | | Date | Thu, 18 May 2023 16:13:41 -0400 | From | Kent Overstreet <> | Subject | Re: [RFC PATCH 1/5] mm: intorduce __GFP_UNMAPPED and unmapped_alloc() |
| |
On Thu, May 18, 2023 at 01:03:28PM -0700, Song Liu wrote: > If we use compound_order(), we will round up to power of 2 for all > allocations. Does this mean we will use 4MiB for a 2.1MiB allocation?
Yes. This means we lose on average 33% - I believe, someone with better statistics might correct me - to internal fragmentation. But the buddy allocator will be better at avoiding and dealing with external fragmentation over time.
| |