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authorPavel Begunkov <asml.silence@gmail.com>2021-01-09 16:03:01 +0000
committerJens Axboe <axboe@kernel.dk>2021-01-25 08:58:24 -0700
commit54c8195b4ebe10af66b49ab9c809bc16939555fc (patch)
treeda5174573c5b40de7e1e43d1ca65a75d1fcf0ed3 /lib/iov_iter.c
parentecd7fba0ade1d6d8d49d320df9caf96922a376b2 (diff)
downloadlinux-54c8195b4ebe10af66b49ab9c809bc16939555fc.tar.bz2
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 <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'lib/iov_iter.c')
-rw-r--r--lib/iov_iter.c19
1 files changed, 19 insertions, 0 deletions
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);