Commit 934c2999 authored by Sagi Grimberg's avatar Sagi Grimberg Committed by Jakub Kicinski
Browse files

net: micro-optimize skb_datagram_iter 



We only use the mapping in a single context in a short and contained scope,
so kmap_local_page is sufficient and cheaper. This will also allow
skb_datagram_iter to be called from softirq context.

Signed-off-by: default avatarSagi Grimberg <sagi@grimberg.me>
Link: https://lore.kernel.org/r/20240613113504.1079860-1-sagi@grimberg.me


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent abef8495

net/core/datagram.c

+2 −2
Original line number Diff line number Diff line
@@ -417,14 +417,14 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset, 
		end = start + skb_frag_size(frag);

		if ((copy = end - offset) > 0) {

			struct page *page = skb_frag_page(frag);

			u8 *vaddr = kmap(page);

			u8 *vaddr = kmap_local_page(page);



			if (copy > len)

				copy = len;

			n = INDIRECT_CALL_1(cb, simple_copy_to_iter,

					vaddr + skb_frag_off(frag) + offset - start,

					copy, data, to);

			kunmap(page);

			kunmap_local(vaddr);

			offset += n;

			if (n != copy)

				goto short_copy;