Re: [ovs-dev] [PATCH v26 6/8] dpif-netlink: Add netdev offload recv in normal recv upcalls

[Chris Mi via dev]

On 4/12/2023 10:08 PM, Eelco Chaudron wrote:

On 29 Mar 2023, at 13:42, Chris Mi wrote:

In thread handler 0, add netdev offload recv in normal recv upcalls.
To avoid starvation, introduce a flag to alternate the order of
receiving normal upcalls and offload upcalls based on that flag.

One small comment inline.

//Eelco

Add similar change for recv_wait.

Signed-off-by: Chris Mi<c...@nvidia.com>
Reviewed-by: Roi Dayan<r...@nvidia.com>
---
  lib/dpif-netlink.c            | 41 ++++++++++++++++++++++++++++++-----
  ofproto/ofproto-dpif-upcall.c | 15 +++++++++----
  2 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/lib/dpif-netlink.c b/lib/dpif-netlink.c
index ebe7b5cb1..4e56922f8 100644
--- a/lib/dpif-netlink.c
+++ b/lib/dpif-netlink.c
@@ -201,6 +201,11 @@ struct dpif_handler {
      struct nl_sock *sock;         /* Each handler thread holds one netlink
                                       socket. */

+    /* The receive handler thread deals with both normal and offload receive
+     * upcalls. To avoid starvation, the below flag is used to alternate the
+     * processing order. */
+    bool recv_offload_first;
+
  #ifdef _WIN32
      /* Pool of sockets. */
      struct dpif_windows_vport_sock *vport_sock_pool;
@@ -3005,7 +3010,6 @@ dpif_netlink_recv_windows(struct dpif_netlink *dpif, 
uint32_t handler_id,
  static int
  dpif_netlink_recv_cpu_dispatch(struct dpif_netlink *dpif, uint32_t handler_id,
                                 struct dpif_upcall *upcall, struct ofpbuf *buf)
-    OVS_REQ_RDLOCK(dpif->upcall_lock)
  {
      struct dpif_handler *handler;
      int read_tries = 0;
@@ -3056,7 +3060,6 @@ dpif_netlink_recv_vport_dispatch(struct dpif_netlink 
*dpif,
                                   uint32_t handler_id,
                                   struct dpif_upcall *upcall,
                                   struct ofpbuf *buf)
-    OVS_REQ_RDLOCK(dpif->upcall_lock)
  {
      struct dpif_handler *handler;
      int read_tries = 0;
@@ -3130,13 +3133,12 @@ dpif_netlink_recv_vport_dispatch(struct dpif_netlink 
*dpif,
  #endif

  static int
-dpif_netlink_recv(struct dpif *dpif_, uint32_t handler_id,
-                  struct dpif_upcall *upcall, struct ofpbuf *buf)
+dpif_netlink_recv__(struct dpif_netlink *dpif, uint32_t handler_id,
+                    struct dpif_upcall *upcall, struct ofpbuf *buf)
+    OVS_REQ_RDLOCK(dpif->upcall_lock)
  {
-    struct dpif_netlink *dpif = dpif_netlink_cast(dpif_);
      int error;

-    fat_rwlock_rdlock(&dpif->upcall_lock);
  #ifdef _WIN32
      error = dpif_netlink_recv_windows(dpif, handler_id, upcall, buf);
  #else
@@ -3147,6 +3149,32 @@ dpif_netlink_recv(struct dpif *dpif_, uint32_t 
handler_id,
                                                   handler_id, upcall, buf);
      }
  #endif
+
+    return error;
+}
+
+static int
+dpif_netlink_recv(struct dpif *dpif_, uint32_t handler_id,
+                  struct dpif_upcall *upcall, struct ofpbuf *buf)
+{
+    struct dpif_netlink *dpif = dpif_netlink_cast(dpif_);
+    struct dpif_handler *handler;
+    int error;
+
+    fat_rwlock_rdlock(&dpif->upcall_lock);
+    handler = &dpif->handlers[handler_id];
+    if (handler->recv_offload_first) {
+        error = netdev_offload_recv(upcall, buf, handler_id);
+        if (error == EAGAIN) {
+            error = dpif_netlink_recv__(dpif, handler_id, upcall, buf);
+        }
+    } else {
+        error = dpif_netlink_recv__(dpif, handler_id, upcall, buf);
+        if (error == EAGAIN) {
+            error = netdev_offload_recv(upcall, buf, handler_id);
+        }
+    }
+    handler->recv_offload_first = !handler->recv_offload_first;
      fat_rwlock_unlock(&dpif->upcall_lock);

      return error;
@@ -3211,6 +3239,7 @@ dpif_netlink_recv_wait(struct dpif *dpif_, uint32_t 
handler_id)
      } else {
          dpif_netlink_recv_wait_vport_dispatch(dpif, handler_id);
      }
+    netdev_offload_recv_wait(handler_id);
  #endif

Should this netdev_offload_recv_wait(handler_id) not be called outside of the 
'#ifdef _WIN32' as it should not depend on Windows not being the implementation?

Done.

      fat_rwlock_unlock(&dpif->upcall_lock);
  }
diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c
index cd57fdbd9..0b3ef30a0 100644
--- a/ofproto/ofproto-dpif-upcall.c
+++ b/ofproto/ofproto-dpif-upcall.c
@@ -855,10 +855,17 @@ recv_upcalls(struct handler *handler)
              break;
          }

-        upcall->fitness = odp_flow_key_to_flow(dupcall->key, dupcall->key_len,
-                                               flow, NULL);
-        if (upcall->fitness == ODP_FIT_ERROR) {
-            goto free_dupcall;
+        /* If key and key_len are available, use them to construct flow.
+         * Otherwise, use upcall->flow. */
+        if (dupcall->key && dupcall->key_len) {
+            upcall->fitness = odp_flow_key_to_flow(dupcall->key,
+                                                   dupcall->key_len,
+                                                   flow, NULL);
+            if (upcall->fitness == ODP_FIT_ERROR) {
+                goto free_dupcall;
+            }
+        } else {
+            flow = &dupcall->flow;
          }

          if (dupcall->mru) {
--
2.26.3

_______________________________________________
dev mailing list
d...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-dev