Messages in this thread | | | Date | Tue, 18 Feb 2014 11:07:09 -0800 | Subject | Re: [RFC, PATCHv2 0/2] mm: map few pages around fault address if they are in page cache | From | Linus Torvalds <> |
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On Tue, Feb 18, 2014 at 10:53 AM, Matthew Wilcox <willy@linux.intel.com> wrote: > > Yes, I did mean "holepunches and page faults". But here's the race I see:
Hmm. With truncate, we should be protected by i_size being changed first (iirc - I didn't actually check), but I think you're right that hole punching might race with a page being mapped at the same time.
> What I'm suggesting is going back to Kirill's earlier patch, but only > locking the page with the highest index instead of all of the pages. > truncate() will block on that page and then we'll notice that some or > all of the other pages are also now past i_size and give up.
Actually, Kirill's latest patch seems to solve the problem with locking - by simply never locking more than one page at a time. So I guess it's all moot at least wrt the page preload..
Linus
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