| | From | Andy Whitcroft <> | | Subject | [RFC] hugetlb reservations -- MAP_PRIVATE fixes for split vmas V2 | | Date | Mon, 23 Jun 2008 18:35:31 +0100 |
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As reported by Adam Litke and Jon Tollefson one of the libhugetlbfs regression tests triggers a negative overall reservation count. When this occurs where there is no dynamic pool enabled tests will fail.
Following this email are two patches to address this issue:
hugetlb reservations: move region tracking earlier -- simply moves the region tracking code earlier so we do not have to supply prototypes, and
hugetlb reservations: fix hugetlb MAP_PRIVATE reservations across vma splits -- which moves us to tracking the consumed reservation so that we can correctly calculate the remaining reservations at vma close time.
This stack is against the top of v2.6.25-rc6-mm3, should this solution prove acceptable it would need slipping underneath Nick's multiple hugepage size patches and those updated. I have a modified stack prepared for that.
This version incorporates Mel's feedback (both cosmetic, and an allocation under spinlock issue) and has an improved layout.
Changes in V2: - commentry updates - pull allocations out from under hugetlb_lock - refactor to match shared code layout - reinstate BUG_ON's
Jon could you have a test on this and see if it works out for you.
-apw
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