Re: [PATCH v8 02/14] mm/gup: check every subpage of a compound page during isolation
From: Joao Martins <hidden>
Date: 2021-02-03 16:50:45
Also in:
linux-kselftest, linux-mm, lkml
From: Joao Martins <hidden>
Date: 2021-02-03 16:50:45
Also in:
linux-kselftest, linux-mm, lkml
On 2/3/21 3:32 PM, Joao Martins wrote:
On 2/3/21 2:51 PM, Pavel Tatashin wrote:quoted
On Wed, Feb 3, 2021 at 8:23 AM Joao Martins [off-list ref] wrote:quoted
On 1/25/21 7:47 PM, Pavel Tatashin wrote: for compound pages but when !is_transparent_hugepage(head) or just PageHuge(head) like: + if (!is_transparent_hugepage(head) && PageCompound(page)) + i += (compound_nr(head) - (pages[i] - head)); Or making specific to hugetlbfs: + if (PageHuge(head)) + i += (compound_nr(head) - (pages[i] - head));Yes, this is reasonable optimization. I will submit a follow up patch against linux-next.
Realized it late, but the previous step was already broken. And I inherited its brokeness, when copy-pasting the deleted chunk: The @step should be capped at the remaining pages to iterate: i += min(nr_pages - i, compound_nr(head) - (pages[i] - head)); Joao