diff options
| author | Will Deacon <will@kernel.org> | 2025-07-17 10:01:16 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2025-08-01 09:11:09 -0400 |
| commit | 6693731487a8145a9b039bc983d77edc47693855 (patch) | |
| tree | c44caf3ac065084048b962ca92db2a90234fb4c0 | |
| parent | 8ca76151d2c8219edea82f1925a2a25907ff6a9d (diff) | |
vsock/virtio: Allocate nonlinear SKBs for handling large transmit buffers
When transmitting a vsock packet, virtio_transport_send_pkt_info() calls
virtio_transport_alloc_linear_skb() to allocate and fill SKBs with the
transmit data. Unfortunately, these are always linear allocations and
can therefore result in significant pressure on kmalloc() considering
that the maximum packet size (VIRTIO_VSOCK_MAX_PKT_BUF_SIZE +
VIRTIO_VSOCK_SKB_HEADROOM) is a little over 64KiB, resulting in a 128KiB
allocation for each packet.
Rework the vsock SKB allocation so that, for sizes with page order
greater than PAGE_ALLOC_COSTLY_ORDER, a nonlinear SKB is allocated
instead with the packet header in the SKB and the transmit data in the
fragments. Note that this affects both the vhost and virtio transports.
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-10-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | net/vmw_vsock/virtio_transport_common.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index c9eb7f7ac00d2..fe92e5fa95b4d 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -109,7 +109,8 @@ static int virtio_transport_fill_skb(struct sk_buff *skb, return __zerocopy_sg_from_iter(info->msg, NULL, skb, &info->msg->msg_iter, len, NULL); - return memcpy_from_msg(skb_put(skb, len), info->msg, len); + virtio_vsock_skb_put(skb, len); + return skb_copy_datagram_from_iter(skb, 0, &info->msg->msg_iter, len); } static void virtio_transport_init_hdr(struct sk_buff *skb, @@ -261,7 +262,7 @@ static struct sk_buff *virtio_transport_alloc_skb(struct virtio_vsock_pkt_info * if (!zcopy) skb_len += payload_len; - skb = virtio_vsock_alloc_linear_skb(skb_len, GFP_KERNEL); + skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL); if (!skb) return NULL; |