On Mon, 28 Oct 2024 14:13:26 +0000 Lorenzo Stoakes lorenzo.stoakes@oracle.com wrote:
Userland library functions such as allocators and threading implementations often require regions of memory to act as 'guard pages' - mappings which, when accessed, result in a fatal signal being sent to the accessing process.
The current means by which these are implemented is via a PROT_NONE mmap() mapping, which provides the required semantics however incur an overhead of a VMA for each such region.
With a great many processes and threads, this can rapidly add up and incur a significant memory penalty. It also has the added problem of preventing merges that might otherwise be permitted.
This series takes a different approach - an idea suggested by Vlasimil Babka (and before him David Hildenbrand and Jann Horn - perhaps more - the
Nit. s/Vlasimil/Vlastimil/ ;)
Thanks, SJ
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