From 54c8195b4ebe10af66b49ab9c809bc16939555fc Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sat, 9 Jan 2021 16:03:01 +0000 Subject: iov_iter: optimise bvec iov_iter_advance() 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 Signed-off-by: Pavel Begunkov Reviewed-by: Ming Lei Signed-off-by: Jens Axboe --- lib/iov_iter.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'lib') diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 6c597cdfcf5b..e55357f09f71 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); -- cgit v1.2.3