1. 28 3月, 2017 23 次提交
  2. 26 3月, 2017 10 次提交
  3. 25 3月, 2017 7 次提交
    • D
      Merge branch 'epoll-busypoll' · 2239cc63
      David S. Miller 提交于
      Alexander Duyck says:
      
      ====================
      Add busy poll support for epoll
      
      This patch set adds support for using busy polling with epoll. The main
      idea behind this is that we record the NAPI ID for the last event that is
      moved onto the ready list for the epoll context and then when we no longer
      have any events on the ready list we begin polling with that ID. If the
      busy polling does not yield any events then we will reset the NAPI ID to 0
      and wait until a new event is added to the ready list with a valid NAPI ID
      before we will resume busy polling.
      
      Most of the changes in this set authored by me are meant to be cleanup or
      fixes for various things. For example, I am trying to make it so that we
      don't perform hash look-ups for the NAPI instance when we are only working
      with sender_cpu and the like.
      
      At the heart of this set is the last 3 patches which enable epoll support
      and add support for obtaining the NAPI ID of a given socket. With these it
      becomes possible for an application to make use of epoll and get optimal
      busy poll utilization by stacking multiple sockets with the same NAPI ID on
      the same epoll context.
      
      v1: The first version of this series only allowed epoll to busy poll if all
          of the sockets with a NAPI ID shared the same NAPI ID. I feel we were
          too strict with this requirement, so I changed the behavior for v2.
      v2: The second version was pretty much a full rewrite of the first set. The
          main changes consisted of pulling apart several patches to better
          address the need to clean up a few items and to make the code easier to
          review. In the set however I went a bit overboard and was trying to fix
          an issue that would only occur with 500+ years of uptime, and in the
          process limited the range for busy_poll/busy_read unnecessarily.
      v3: Split off the code for limiting busy_poll and busy_read into a separate
          patch for net.
          Updated patch that changed busy loop time tracking so that it uses
          "local_clock() >> 10" as we originally did.
          Tweaked "Change return type.." patch by moving declaration of "work"
          inside the loop where is was accessed and always reset to 0.
          Added "Acked-by" for patches that received acks.
      ====================
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2239cc63
    • S
      net: Introduce SO_INCOMING_NAPI_ID · 6d433902
      Sridhar Samudrala 提交于
      This socket option returns the NAPI ID associated with the queue on which
      the last frame is received. This information can be used by the apps to
      split the incoming flows among the threads based on the Rx queue on which
      they are received.
      
      If the NAPI ID actually represents a sender_cpu then the value is ignored
      and 0 is returned.
      Signed-off-by: NSridhar Samudrala <sridhar.samudrala@intel.com>
      Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6d433902
    • S
      epoll: Add busy poll support to epoll with socket fds. · bf3b9f63
      Sridhar Samudrala 提交于
      This patch adds busy poll support to epoll. The implementation is meant to
      be opportunistic in that it will take the NAPI ID from the last socket
      that is added to the ready list that contains a valid NAPI ID and it will
      use that for busy polling until the ready list goes empty.  Once the ready
      list goes empty the NAPI ID is reset and busy polling is disabled until a
      new socket is added to the ready list.
      
      In addition when we insert a new socket into the epoll we record the NAPI
      ID and assume we are going to receive events on it.  If that doesn't occur
      it will be evicted as the active NAPI ID and we will resume normal
      behavior.
      
      An application can use SO_INCOMING_CPU or SO_REUSEPORT_ATTACH_C/EBPF socket
      options to spread the incoming connections to specific worker threads
      based on the incoming queue. This enables epoll for each worker thread
      to have only sockets that receive packets from a single queue. So when an
      application calls epoll_wait() and there are no events available to report,
      busy polling is done on the associated queue to pull the packets.
      Signed-off-by: NSridhar Samudrala <sridhar.samudrala@intel.com>
      Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      bf3b9f63
    • S
      net: Commonize busy polling code to focus on napi_id instead of socket · 7db6b048
      Sridhar Samudrala 提交于
      Move the core functionality in sk_busy_loop() to napi_busy_loop() and
      make it independent of sk.
      
      This enables re-using this function in epoll busy loop implementation.
      Signed-off-by: NSridhar Samudrala <sridhar.samudrala@intel.com>
      Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7db6b048
    • A
      net: Track start of busy loop instead of when it should end · 37056719
      Alexander Duyck 提交于
      This patch flips the logic we were using to determine if the busy polling
      has timed out.  The main motivation for this is that we will need to
      support two different possible timeout values in the future and by
      recording the start time rather than when we would want to end we can focus
      on making the end_time specific to the task be it epoll or socket based
      polling.
      Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      37056719
    • A
      net: Change return type of sk_busy_loop from bool to void · 2b5cd0df
      Alexander Duyck 提交于
      checking the return value of sk_busy_loop. As there are only a few
      consumers of that data, and the data being checked for can be replaced
      with a check for !skb_queue_empty() we might as well just pull the code
      out of sk_busy_loop and place it in the spots that actually need it.
      Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2b5cd0df
    • A
      net: Only define skb_mark_napi_id in one spot instead of two · d2e64dbb
      Alexander Duyck 提交于
      Instead of defining two versions of skb_mark_napi_id I think it is more
      readable to just match the format of the sk_mark_napi_id functions and just
      wrap the contents of the function instead of defining two versions of the
      function.  This way we can save a few lines of code since we only need 2 of
      the ifdef/endif but needed 5 for the extra function declaration.
      Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d2e64dbb