From: Matthew Wilcox <willy@infradead.org>
To: Jann Horn <jannh@google.com>
Cc: linux-mm@kvack.org, Arjun Roy <arjunroy@google.com>,
Eric Dumazet <edumazet@google.com>,
Suren Baghdasaryan <surenb@google.com>,
linux-fsdevel@vger.kernel.org,
Punit Agrawal <punit.agrawal@bytedance.com>
Subject: Re: [PATCH v2 4/9] mm: Move FAULT_FLAG_VMA_LOCK check into handle_pte_fault()
Date: Mon, 24 Jul 2023 17:37:01 +0100 [thread overview]
Message-ID: <ZL6orfmFWyekqSv1@casper.infradead.org> (raw)
In-Reply-To: <CAG48ez3jouPFr2j3=06jezeO61qdJNR=eK7OednhCgRU+Y_bYg@mail.gmail.com>
On Mon, Jul 24, 2023 at 05:46:57PM +0200, Jann Horn wrote:
> On Tue, Jul 11, 2023 at 10:20 PM Matthew Wilcox (Oracle)
> <willy@infradead.org> wrote:
> > Push the check down from __handle_mm_fault(). There's a mild upside to
> > this patch in that we'll allocate the page tables while under the VMA
> > lock rather than the mmap lock, reducing the hold time on the mmap lock,
> > since the retry will find the page tables already populated.
>
> This commit, by moving the check from __handle_mm_fault() to
> handle_pte_fault(), also makes the non-anonymous THP paths (including
> the DAX huge fault handling) reachable for VMA-locked faults, right?
> Is that intentional?
Oof, this patch is all kinds of buggy. Will split this into several
pieces. Thanks!
next prev parent reply other threads:[~2023-07-24 16:37 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-11 20:20 [PATCH v2 0/9] Avoid the mmap lock for fault-around Matthew Wilcox (Oracle)
2023-07-11 20:20 ` [PATCH v2 1/9] Revert "tcp: Use per-vma locking for receive zerocopy" Matthew Wilcox (Oracle)
2023-07-14 3:02 ` Suren Baghdasaryan
2023-07-14 3:34 ` Matthew Wilcox
2023-07-24 14:49 ` Jann Horn
2023-07-24 15:06 ` Matthew Wilcox
2023-07-24 21:42 ` Jakub Kicinski
2023-07-11 20:20 ` [PATCH v2 2/9] mm: Allow per-VMA locks on file-backed VMAs Matthew Wilcox (Oracle)
2023-07-14 3:03 ` Suren Baghdasaryan
2023-07-11 20:20 ` [PATCH v2 3/9] mm: Move FAULT_FLAG_VMA_LOCK check from handle_mm_fault() Matthew Wilcox (Oracle)
2023-07-14 3:04 ` Suren Baghdasaryan
2023-07-11 20:20 ` [PATCH v2 4/9] mm: Move FAULT_FLAG_VMA_LOCK check into handle_pte_fault() Matthew Wilcox (Oracle)
2023-07-14 3:17 ` Suren Baghdasaryan
2023-07-24 15:46 ` Jann Horn
2023-07-24 16:37 ` Matthew Wilcox [this message]
2023-07-11 20:20 ` [PATCH v2 5/9] mm: Move FAULT_FLAG_VMA_LOCK check down in handle_pte_fault() Matthew Wilcox (Oracle)
2023-07-14 3:26 ` Suren Baghdasaryan
2023-07-24 15:46 ` Jann Horn
2023-07-24 17:45 ` Matthew Wilcox
2023-07-11 20:20 ` [PATCH v2 6/9] mm: Move the FAULT_FLAG_VMA_LOCK check down from do_fault() Matthew Wilcox (Oracle)
2023-07-14 3:27 ` Suren Baghdasaryan
2023-07-11 20:20 ` [PATCH v2 7/9] mm: Run the fault-around code under the VMA lock Matthew Wilcox (Oracle)
2023-07-14 3:32 ` Suren Baghdasaryan
2023-07-24 17:38 ` Matthew Wilcox
2023-07-11 20:20 ` [PATCH v2 8/9] mm: Remove CONFIG_PER_VMA_LOCK ifdefs Matthew Wilcox (Oracle)
2023-07-14 3:34 ` Suren Baghdasaryan
2023-07-11 20:20 ` [PATCH v2 9/9] tcp: Use per-vma locking for receive zerocopy Matthew Wilcox (Oracle)
2023-07-14 3:40 ` Suren Baghdasaryan
2023-07-21 18:48 ` Matthew Wilcox
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