Re: [PATCH RFC] mm/madvise: introduce MADV_POPULATE to prefault/prealloc memory

David Hildenbrand
2021-02-18T13:07:05Z

> Am 18.02.2021 um 12:15 schrieb Rolf Eike Beer <eike-kernel@sf-tec.de>:
>
> ﻿
>>
>>> Let's introduce MADV_POPULATE with the following semantics
>>> 1. MADV_POPULATED does not work on PROT_NONE and special VMAs. It works
>>> on everything else.
>>> 2. Errors during MADV_POPULATED (especially OOM) are reported. If we hit
>>> hardware errors on pages, ignore them - nothing we really can or
>>> should do.
>>> 3. On errors during MADV_POPULATED, some memory might have been
>>> populated. Callers have to clean up if they care.
>>> 4. Concurrent changes to the virtual memory layour are tolerated - we
> ^t
>>> process each and every PFN only once, though.
>>> 5. If MADV_POPULATE succeeds, all memory in the range can be accessed
>>> without SIGBUS. (of course, not if user space changed mappings in the
>>> meantime or KSM kicked in on anonymous memory).
>
> You are talking both about MADV_POPULATE and MADV_POPULATED here.
>

Already fixed up :) thanks!

> Eike
>