hugetlb: simplify prep_compound_gigantic_page ref count racing code

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Code in prep_compound_gigantic_page waits for a rcu grace period if it
notices a temporarily inflated ref count on a tail page.  This was due to
the identified potential race with speculative page cache references which
could only last for a rcu grace period.  This is overly complicated as
this situation is VERY unlikely to ever happen.  Instead, just quickly
return an error.

Also, only print a warning in prep_compound_gigantic_page instead of
multiple callers.

Link: https://lkml.kernel.org/r/20210809184832.18342-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

...

This commit is contained in:

Mike Kravetz 2021-09-02 14:58:43 -07:00 • committed by Linus Torvalds

parent f87060d345

commit 416d85ed3e

1 changed files with 7 additions and 10 deletions

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mm/hugetlb.c

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