[ovs-dev] [PATCH v9 1/6] netdev-dpdk: Restore thread affinity after DPDK init

Aaron Conole aconole at redhat.com
Thu Feb 11 20:15:36 UTC 2016


When the DPDK init function is called, it changes the executing thread's
CPU affinity to a single core specified in -c. This will result in the
userspace bridge configuration thread being rebound, even if that is not
the intent.

This change fixes that behavior by rebinding to the original thread
affinity after calling dpdk_init().

Signed-off-by: Kevin Traynor <kevin.traynor at intel.com>
Signed-off-by: Aaron Conole <aconole at redhat.com>
Tested-by: RobertX Wojciechowicz <robertx.wojciechowicz at intel.com>
Acked-by: Panu Matilainen <pmatilai at redhat.com>
Acked-by: Flavio Leitner <fbl at sysclose.org>
---
v2:
* Removed trailing whitespace

v3->v9:
* No change

 lib/netdev-dpdk.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index e4f789b..cf63b4d 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -2241,6 +2241,9 @@ dpdk_init(int argc, char **argv)
     int result;
     int base = 0;
     char *pragram_name = argv[0];
+    int err;
+    int isset;
+    cpu_set_t cpuset;
 
     if (argc < 2 || strcmp(argv[1], "--dpdk"))
         return 0;
@@ -2282,6 +2285,14 @@ dpdk_init(int argc, char **argv)
         base = 2;
     }
 
+    /* Get the main thread affinity */
+    CPU_ZERO(&cpuset);
+    err = pthread_getaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
+    if (err) {
+        VLOG_ERR("Thread getaffinity error %d.", err);
+        return err;
+    }
+
     /* Keep the program name argument as this is needed for call to
      * rte_eal_init()
      */
@@ -2293,6 +2304,13 @@ dpdk_init(int argc, char **argv)
         ovs_abort(result, "Cannot init EAL");
     }
 
+    /* Set the main thread affinity back to pre rte_eal_init() value */
+    err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
+    if (err) {
+        VLOG_ERR("Thread setaffinity error %d", err);
+        return err;
+    }
+
     rte_memzone_dump(stdout);
     rte_eal_init_ret = 0;
 
-- 
2.5.0




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