Messages in this thread | ![/](/images/icornerl.gif) | | From | "Hillf Danton" <> | Subject | Re: [PATCH -v4 RESEND 8/9] mm, THP, swap: Support to split THP in swap cache | Date | Fri, 28 Oct 2016 18:18:34 +0800 |
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On Friday, October 28, 2016 1:56 PM Huang, Ying wrote: > @@ -2016,10 +2021,12 @@ int page_trans_huge_mapcount(struct page *page, int *total_mapcount) > /* Racy check whether the huge page can be split */ > bool can_split_huge_page(struct page *page) > { > - int extra_pins = 0; > + int extra_pins; > > /* Additional pins from radix tree */ > - if (!PageAnon(page)) > + if (PageAnon(page)) > + extra_pins = PageSwapCache(page) ? HPAGE_PMD_NR : 0; > + else > extra_pins = HPAGE_PMD_NR;
extra_pins is computed in this newly added helper.
> return total_mapcount(page) == page_count(page) - extra_pins - 1; > } > @@ -2072,7 +2079,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) > ret = -EBUSY; > goto out; > } > - extra_pins = 0; > + extra_pins = PageSwapCache(head) ? HPAGE_PMD_NR : 0;
It is also computed at the call site, so can we fold them into one?
> mapping = NULL; > anon_vma_lock_write(anon_vma); > } else { > -- > 2.9.3
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