-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
tap: use build_skb() for small packet
We use tun_alloc_skb() which calls sock_alloc_send_pskb() to allocate skb in the past. This socket based method is not suitable for high speed userspace like virtualization which usually: - ignore sk_sndbuf (INT_MAX) and expect to receive the packet as fast as possible - don't want to be block at sendmsg() To eliminate the above overheads, this patch tries to use build_skb() for small packet. We will do this only when the following conditions are all met: - TAP instead of TUN - sk_sndbuf is INT_MAX - caller don't want to be blocked - zerocopy is not used - packet size is smaller enough to use build_skb() Pktgen from guest to host shows ~11% improvement for rx pps of tap: Before: ~1.70Mpps After : ~1.88Mpps What's more important, this makes it possible to implement XDP for tap before creating skbs. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
- Loading branch information
Jason Wang
authored and
David S. Miller
committed
Aug 14, 2017
1 parent
d022578
commit 66ccbc9
Showing
1 changed file
with
91 additions
and
21 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters