Messages in this thread |  | | Date | Mon, 10 Aug 2020 10:17:37 +0800 | From | Baoquan He <> | Subject | Re: [PATCH 10/10] mm/hugetlb: not necessary to abuse temporary page to workaround the nasty free_huge_page |
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On 08/07/20 at 05:12pm, Wei Yang wrote: > Let's always increase surplus_huge_pages and so that free_huge_page > could decrease it at free time. > > Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> > --- > mm/hugetlb.c | 14 ++++++-------- > 1 file changed, 6 insertions(+), 8 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 1f2010c9dd8d..a0eb81e0e4c5 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1913,21 +1913,19 @@ static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask, > return NULL; > > spin_lock(&hugetlb_lock); > + > + h->surplus_huge_pages++; > + h->surplus_huge_pages_node[page_to_nid(page)]++; > + > /* > * We could have raced with the pool size change. > * Double check that and simply deallocate the new page > - * if we would end up overcommiting the surpluses. Abuse > - * temporary page to workaround the nasty free_huge_page > - * codeflow > + * if we would end up overcommiting the surpluses. > */ > - if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) { > - SetPageHugeTemporary(page);
Hmm, the temporary page way is taken intentionally in commit 9980d744a0428 ("mm, hugetlb: get rid of surplus page accounting tricks"). From code, this is done inside hugetlb_lock holding, and the code flow is straightforward, should be safe. Adding Michal to CC.
> + if (h->surplus_huge_pages > h->nr_overcommit_huge_pages) { > spin_unlock(&hugetlb_lock); > put_page(page); > return NULL; > - } else { > - h->surplus_huge_pages++; > - h->surplus_huge_pages_node[page_to_nid(page)]++; > } > > out_unlock: > -- > 2.20.1 (Apple Git-117) > >
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