Messages in this thread | | | Date | Thu, 8 Apr 2021 09:00:26 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH 24/37] mm: implement speculative handling in __do_fault() |
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On Wed, Apr 07, 2021 at 10:27:12PM +0100, Matthew Wilcox wrote: > Doing I/O without any lock held already works; it just uses the file > refcount. It would be better to use a vma refcount, as I already said.
The original workload that I developed SPF for (waaaay back when) was prefaulting a single huge vma. Using a vma refcount was a total loss because it resulted in the same cacheline contention that down_read() was having.
As such, I'm always incredibly sad to see mention of vma refcounts. They're fundamentally not solving the problem :/
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