On Thu 19-01-17 01:09:35, John Hubbard wrote: [...] > So that leaves us with maybe this for documentation? > > * Reclaim modifiers - __GFP_NORETRY and __GFP_NOFAIL should not be passed in. > * Passing in __GFP_REPEAT is supported, and will cause the following > behavior: > * for larger (>64KB) allocations, the first part (kmalloc) will do some > * retrying, before falling back to vmalloc.
I am worried this is just too vague. It doesn't really help user to decide whether "do some retrying" is what he really want's or needs. So I would rather see the following. " * Reclaim modifiers - __GFP_NORETRY and __GFP_NOFAIL are not supported. __GFP_REPEAT * is supported only for large (>32kB) allocations and it should be used when using * kmalloc is preferable because vmalloc fallback has visible performance drawbacks. " I would also add " Any use of gfp flags outside of GFP_KERNEL should be consulted with mm people. " Does it sound any better? -- Michal Hocko SUSE Labs
