linux-kernel - Re: [PATCH v2 4/6] mm: drop VMA lock before waiting for migration

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Message-ID: <ZIdqjoh+C6gNdlHY@x1n>
Date:   Mon, 12 Jun 2023 14:57:18 -0400
From:   Peter Xu <peterx@...hat.com>
To:     Suren Baghdasaryan <surenb@...gle.com>
Cc:     akpm@...ux-foundation.org, willy@...radead.org, hannes@...xchg.org,
        mhocko@...e.com, josef@...icpanda.com, jack@...e.cz,
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Subject: Re: [PATCH v2 4/6] mm: drop VMA lock before waiting for migration

On Mon, Jun 12, 2023 at 11:44:33AM -0700, Suren Baghdasaryan wrote:
> I think so. With that change getting VM_FAULT_RETRY in do_page_fault()
> will guarantee that per-vma lock was dropped. Is that what you mean?

Yes, with the newly added "return VM_FAULT_RETRY" in do_swap_page() for
per-vma lock removed.  AFAICT all the rest paths guaranteed that as long as
in the fault paths.

-- 
Peter Xu