From: Pavel Begunkov <asml.silence@gmail.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] iov_iter: optimise bvec iov_iter_advance()
Date: Thu, 3 Dec 2020 01:45:54 +0000 [thread overview]
Message-ID: <21b78c2f256e513b9eb3f22c7c1f55fc88992600.1606957658.git.asml.silence@gmail.com> (raw)
iov_iter_advance() is heavily used, but implemented through generic
iteration. As bvecs have a specifically crafted advance() function, i.e.
bvec_iter_advance(), which is faster and slimmer, use it instead.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
lib/iov_iter.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 1635111c5bd2..7fbdd9ef3ff0 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1077,6 +1077,20 @@ void iov_iter_advance(struct iov_iter *i, size_t size)
i->count -= size;
return;
}
+ if (iov_iter_is_bvec(i)) {
+ struct bvec_iter bi;
+
+ bi.bi_size = i->count;
+ bi.bi_bvec_done = i->iov_offset;
+ bi.bi_idx = 0;
+ bvec_iter_advance(i->bvec, &bi, size);
+
+ i->bvec += bi.bi_idx;
+ i->nr_segs -= bi.bi_idx;
+ i->count = bi.bi_size;
+ i->iov_offset = bi.bi_bvec_done;
+ return;
+ }
iterate_and_advance(i, size, v, 0, 0, 0)
}
EXPORT_SYMBOL(iov_iter_advance);
--
2.24.0
next reply other threads:[~2020-12-03 1:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-03 1:45 Pavel Begunkov [this message]
2020-12-03 9:14 ` [PATCH] iov_iter: optimise bvec iov_iter_advance() Christoph Hellwig
2020-12-03 11:48 ` Pavel Begunkov
2020-12-09 8:33 ` Christoph Hellwig
2020-12-09 12:06 ` Pavel Begunkov
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