Messages in this thread | | | From | Shakeel Butt <> | Date | Sat, 20 Nov 2021 21:25:27 -0800 | Subject | Re: [PATCH] mm: split thp synchronously on MADV_DONTNEED |
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On Sat, Nov 20, 2021 at 8:35 PM Matthew Wilcox <willy@infradead.org> wrote: > > On Sat, Nov 20, 2021 at 12:12:30PM -0800, Shakeel Butt wrote: > > This patch let such applications not worry about the low level handling > > of THPs in the kernel and splits the THPs synchronously on > > MADV_DONTNEED. > > I don't mind the synchronous split, but I have concerns about the > implementation. I don't think it's worth another pointer in task_struct.
Are you concerned about the size of task_struct? At least on my config this additional pointer was just filling the holes and not increasing the size. I can check a couple other configs as well.
> It's also the case that splitting is likely to succeed, so I think a > better implementation would try to split and then put the page on the > global deferred list if splitting fails.
Actually this is what this patch is doing. See the second loop in split_local_deferred_list().
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