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    SubjectRe: [PATCH 0/6] shmem: high order folios support in write path
    On Fri, Sep 15, 2023 at 05:36:27PM +0200, David Hildenbrand wrote:
    > On 15.09.23 17:34, Matthew Wilcox wrote:
    > > No, it can't. This patchset triggers only on write, not on read or page
    > > fault, and it's conservative, so it will only allocate folios which are
    > > entirely covered by the write. IOW this is memory we must allocate in
    > > order to satisfy the write; we're just allocating it in larger chunks
    > > when we can.
    >
    > Oh, good! I was assuming you would eventually over-allocate on the write
    > path.

    We might! But that would be a different patchset, and it would be
    subject to its own discussion.

    Something else I've been wondering about is possibly reallocating the
    pages on a write. This would apply to both normal files and shmem.
    If you read in a file one byte at a time, then overwrite a big chunk of
    it with a large single write, that seems like a good signal that maybe
    we should manage that part of the file as a single large chunk instead
    of individual pages. Maybe.

    Lots of things for people who are obsessed with performance to play
    with ;-)

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