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From:   David Howells <dhowells@redhat.com>
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To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     dhowells@redhat.com, Pavel Begunkov <asml.silence@gmail.com>,
        Matthew Wilcox <willy@infradead.org>,
        Jens Axboe <axboe@kernel.dk>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
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Subject: Re: [PATCH 01/29] iov_iter: Switch to using a table of operations
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Date:   Sun, 22 Nov 2020 13:33:04 +0000
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Linus Torvalds <torvalds@linux-foundation.org> wrote:

>  - I worry a bit about the indirect call overhead and spectre v2.

I don't know enough about how spectre v2 works to say if this would be a
problem for the ops-table approach, but wouldn't it also affect the chain of
conditional branches that we currently use, since it's branch-prediction
based?

David