Re: hugetlb page patch for 2.5.48-bug fixes

[William Lee Irwin III <wli@holomorphy.com>]

On Thu, Nov 21, 2002 at 02:05:53PM -0800, Rohit Seth wrote:
> Linus, Andrew,
> Attached is the hugetlbpage patch for 2.5.48 containing following main 
> changes:
> 1) Bug fixes (mainly in the unsuccessful attempts of hugepages).
> 2) Removal of Radix Tree field in key structure (as it is not needed).
> 3) Include the IPC_LOCK for permission to use hugepages.
> 4) Increment the key_counts during forks.

Okay, first off why are you using a list linked through page->private?
page->list is fully available for such tasks.

Second, the if (key == NULL) check in hugetlb_release_key() is bogus;
someone is forgetting to check for NULL, probably in
alloc_shared_hugetlb_pages().

Third, the hugetlb_release_key() in unmap_hugepage_range() is the one
that should be removed [along with its corresponding mark_key_busy()],
not the one in sys_free_hugepages(). unmap_hugepage_range() is doing
neither setup nor teardown of the key itself, only the pages and PTE's.
I would say key-level refcounting belongs to sys_free_hugepages().

Bill