From: Pavel Begunkov <[email protected]>
To: [email protected]
Cc: Jens Axboe <[email protected]>,
Christoph Hellwig <[email protected]>,
Matthew Wilcox <[email protected]>,
Ming Lei <[email protected]>,
Johannes Weiner <[email protected]>,
Alexander Viro <[email protected]>,
"Darrick J . Wong" <[email protected]>,
"Martin K . Petersen" <[email protected]>,
Jonathan Corbet <[email protected]>,
[email protected], [email protected],
[email protected], [email protected],
[email protected], [email protected],
[email protected]
Subject: [PATCH v1 2/6] iov_iter: optimise bvec iov_iter_advance()
Date: Tue, 15 Dec 2020 00:20:21 +0000 [thread overview]
Message-ID: <5c9c22dbeecad883ca29b31896c262a8d2a77132.1607976425.git.asml.silence@gmail.com> (raw)
In-Reply-To: <[email protected]>
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 <[email protected]>
---
lib/iov_iter.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 1635111c5bd2..5b186dc2c9ea 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1067,6 +1067,21 @@ static void pipe_advance(struct iov_iter *i, size_t size)
pipe_truncate(i);
}
+static void iov_iter_bvec_advance(struct iov_iter *i, size_t size)
+{
+ 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;
+}
+
void iov_iter_advance(struct iov_iter *i, size_t size)
{
if (unlikely(iov_iter_is_pipe(i))) {
@@ -1077,6 +1092,10 @@ void iov_iter_advance(struct iov_iter *i, size_t size)
i->count -= size;
return;
}
+ if (iov_iter_is_bvec(i)) {
+ iov_iter_bvec_advance(i, size);
+ return;
+ }
iterate_and_advance(i, size, v, 0, 0, 0)
}
EXPORT_SYMBOL(iov_iter_advance);
--
2.24.0
next prev parent reply other threads:[~2020-12-15 0:25 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 0:20 [PATCH v1 0/6] no-copy bvec Pavel Begunkov
2020-12-15 0:20 ` [PATCH v1 1/6] target/file: allocate the bvec array as part of struct target_core_file_cmd Pavel Begunkov
2020-12-15 0:20 ` Pavel Begunkov [this message]
2020-12-15 9:37 ` [PATCH v1 2/6] iov_iter: optimise bvec iov_iter_advance() David Laight
2020-12-15 11:23 ` Pavel Begunkov
2020-12-15 13:54 ` David Laight
2020-12-15 13:56 ` Pavel Begunkov
2020-12-22 14:03 ` Christoph Hellwig
2020-12-15 0:20 ` [PATCH v1 3/6] bio: deduplicate adding a page into bio Pavel Begunkov
2020-12-22 14:04 ` Christoph Hellwig
2020-12-15 0:20 ` [PATCH v1 4/6] block/psi: remove PSI annotations from direct IO Pavel Begunkov
2020-12-15 0:56 ` Dave Chinner
2020-12-15 1:03 ` Pavel Begunkov
2020-12-15 1:33 ` Dave Chinner
2020-12-15 11:41 ` Pavel Begunkov
2020-12-22 14:07 ` Christoph Hellwig
2020-12-15 0:20 ` [PATCH v1 5/6] bio: add a helper calculating nr segments to alloc Pavel Begunkov
2020-12-15 1:00 ` Dave Chinner
2020-12-15 1:07 ` Pavel Begunkov
2020-12-15 1:09 ` Dave Chinner
2020-12-22 14:07 ` Christoph Hellwig
2020-12-15 0:20 ` [PATCH v1 6/6] block/iomap: don't copy bvec for direct IO Pavel Begunkov
2020-12-15 1:09 ` Dave Chinner
2020-12-15 1:15 ` Pavel Begunkov
2020-12-22 14:15 ` Christoph Hellwig
2020-12-15 1:41 ` [PATCH v1 0/6] no-copy bvec Ming Lei
2020-12-15 11:14 ` Pavel Begunkov
2020-12-15 12:03 ` Ming Lei
2020-12-15 14:05 ` Pavel Begunkov
2020-12-22 14:11 ` Christoph Hellwig
2020-12-23 12:52 ` Pavel Begunkov
2020-12-23 15:51 ` Christoph Hellwig
2020-12-23 16:04 ` James Bottomley
2020-12-23 20:23 ` Douglas Gilbert
2020-12-23 20:32 ` Pavel Begunkov
2020-12-24 6:41 ` Christoph Hellwig
2020-12-24 16:45 ` Douglas Gilbert
2020-12-24 17:30 ` James Bottomley
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