From: Pavel Begunkov <asml.silence@gmail.com>
To: linux-block@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>,
Christoph Hellwig <hch@infradead.org>,
Matthew Wilcox <willy@infradead.org>,
Ming Lei <ming.lei@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
"Darrick J . Wong" <darrick.wong@oracle.com>,
"Martin K . Petersen" <martin.petersen@oracle.com>,
Jonathan Corbet <corbet@lwn.net>,
linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
io-uring@vger.kernel.org, linux-kernel@vger.kernel.org,
target-devel@vger.kernel.org, linux-scsi@vger.kernel.org,
linux-doc@vger.kernel.org, Christoph Hellwig <hch@lst.de>
Subject: [PATCH v2 5/7] iov_iter: optimise bvec iov_iter_advance()
Date: Sat, 2 Jan 2021 15:17:37 +0000 [thread overview]
Message-ID: <a93a17ce2669c8f8ec4341bfbc503e2f649c317c.1609461359.git.asml.silence@gmail.com> (raw)
In-Reply-To: <cover.1609461359.git.asml.silence@gmail.com>
iov_iter_advance() is heavily used, but implemented through generic
means. For bvecs there is a specifically crafted function for that, so
use bvec_iter_advance() instead, it's faster and slimmer.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
lib/iov_iter.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 7de304269641..9b1c109dc8a9 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1065,6 +1065,21 @@ 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))) {
@@ -1075,6 +1090,10 @@ 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:[~2021-01-02 15:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-02 15:17 [PATCH v2 0/7] no-copy bvec Pavel Begunkov
2021-01-02 15:17 ` [PATCH v2 1/7] splice: don't generate zero-len segement bvecs Pavel Begunkov
2021-01-04 16:17 ` Christoph Hellwig
2021-01-04 16:54 ` Pavel Begunkov
2021-01-02 15:17 ` [PATCH v2 2/7] bvec/iter: disallow zero-length segment bvecs Pavel Begunkov
2021-01-04 16:18 ` Christoph Hellwig
2021-01-04 16:37 ` Matthew Wilcox
2021-01-04 17:23 ` Pavel Begunkov
2021-01-02 15:17 ` [PATCH v2 3/7] block/psi: remove PSI annotations from direct IO Pavel Begunkov
2021-01-04 16:45 ` Christoph Hellwig
2021-01-02 15:17 ` [PATCH v2 4/7] target/file: allocate the bvec array as part of struct target_core_file_cmd Pavel Begunkov
2021-01-02 15:17 ` Pavel Begunkov [this message]
2021-01-02 15:17 ` [PATCH v2 6/7] bio: add a helper calculating nr segments to alloc Pavel Begunkov
2021-01-02 15:17 ` [PATCH v2 7/7] bio: don't copy bvec for direct IO Pavel Begunkov
2021-01-04 16:20 ` Christoph Hellwig
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