Messages in this thread Patch in this message | | | From | Pasha Tatashin <> | Subject | [RFC 2/8] mm/hugetlb: remove useless set_page_count() | Date | Tue, 26 Oct 2021 17:38:16 +0000 |
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prep_compound_gigantic_page() calls set_page_count(0, p), but it is not needed because page_ref_freeze(p, 1) already sets refcount to 0.
Using, set_page_count() is dangerous, because it unconditionally resets refcount from the current value to unrestrained value, and therefore should be minimized.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> --- mm/hugetlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 95dc7b83381f..7e3996c8b696 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1707,7 +1707,7 @@ static bool prep_compound_gigantic_page(struct page *page, unsigned int order) pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n"); goto out_error; } - set_page_count(p, 0); + VM_BUG_ON_PAGE(page_count(p), p); set_compound_head(p, page); } atomic_set(compound_mapcount_ptr(page), -1); -- 2.33.0.1079.g6e70778dc9-goog
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