1. 04 Aug, 2017 3 commits
    • Willem de Bruijn's avatar
      sock: add MSG_ZEROCOPY · 52267790
      Willem de Bruijn authored
      The kernel supports zerocopy sendmsg in virtio and tap. Expand the
      infrastructure to support other socket types. Introduce a completion
      notification channel over the socket error queue. Notifications are
      returned with ee_origin SO_EE_ORIGIN_ZEROCOPY. ee_errno is 0 to avoid
      blocking the send/recv path on receiving notifications.
      
      Add reference counting, to support the skb split, merge, resize and
      clone operations possible with SOCK_STREAM and other socket types.
      
      The patch does not yet modify any datapaths.
      Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      52267790
    • Willem de Bruijn's avatar
      sock: skb_copy_ubufs support for compound pages · 3ece7826
      Willem de Bruijn authored
      Refine skb_copy_ubufs to support compound pages. With upcoming TCP
      zerocopy sendmsg, such fragments may appear.
      
      The existing code replaces each page one for one. Splitting each
      compound page into an independent number of regular pages can result
      in exceeding limit MAX_SKB_FRAGS if data is not exactly page aligned.
      
      Instead, fill all destination pages but the last to PAGE_SIZE.
      Split the existing alloc + copy loop into separate stages:
      1. compute bytelength and minimum number of pages to store this.
      2. allocate
      3. copy, filling each page except the last to PAGE_SIZE bytes
      4. update skb frag array
      Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3ece7826
    • Willem de Bruijn's avatar
      sock: allocate skbs from optmem · 98ba0bd5
      Willem de Bruijn authored
      Add sock_omalloc and sock_ofree to be able to allocate control skbs,
      for instance for looping errors onto sk_error_queue.
      
      The transmit budget (sk_wmem_alloc) is involved in transmit skb
      shaping, most notably in TCP Small Queues. Using this budget for
      control packets would impact transmission.
      Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      98ba0bd5
  2. 03 Aug, 2017 37 commits