lkml.org 
[lkml]   [2019]   [May]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v2 4/8] vsock/virtio: reduce credit update messages
    Date
    In order to reduce the number of credit update messages,
    we send them only when the space available seen by the
    transmitter is less than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE.

    Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
    ---
    include/linux/virtio_vsock.h | 1 +
    net/vmw_vsock/virtio_transport_common.c | 16 +++++++++++++---
    2 files changed, 14 insertions(+), 3 deletions(-)

    diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
    index fb5954fc85c8..84b72026d327 100644
    --- a/include/linux/virtio_vsock.h
    +++ b/include/linux/virtio_vsock.h
    @@ -41,6 +41,7 @@ struct virtio_vsock_sock {
    /* Protected by rx_lock */
    u32 buf_alloc;
    u32 fwd_cnt;
    + u32 last_fwd_cnt;
    u32 rx_bytes;
    struct list_head rx_queue;
    };
    diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
    index f2e4e128bc86..b61fd5e29a1f 100644
    --- a/net/vmw_vsock/virtio_transport_common.c
    +++ b/net/vmw_vsock/virtio_transport_common.c
    @@ -247,6 +247,7 @@ static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, u32 len)
    void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
    {
    spin_lock_bh(&vvs->rx_lock);
    + vvs->last_fwd_cnt = vvs->fwd_cnt;
    pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
    pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
    spin_unlock_bh(&vvs->rx_lock);
    @@ -297,6 +298,7 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
    struct virtio_vsock_sock *vvs = vsk->trans;
    struct virtio_vsock_buf *buf;
    size_t bytes, total = 0;
    + u32 free_space;
    int err = -EFAULT;

    spin_lock_bh(&vvs->rx_lock);
    @@ -327,11 +329,19 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
    virtio_transport_free_buf(buf);
    }
    }
    +
    + free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);
    +
    spin_unlock_bh(&vvs->rx_lock);

    - /* Send a credit pkt to peer */
    - virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
    - NULL);
    + /* We send a credit update only when the space available seen
    + * by the transmitter is less than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE
    + */
    + if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
    + virtio_transport_send_credit_update(vsk,
    + VIRTIO_VSOCK_TYPE_STREAM,
    + NULL);
    + }

    return total;

    --
    2.20.1
    \
     
     \ /
      Last update: 2019-05-10 15:00    [W:2.125 / U:0.216 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site