[dpdk-dev] [PATCH] Fixed spam from kni_allocate_mbufs() when no mbufs are free. If mbufs exhausted, 'out of memory' message logged at EXTREMELY high rates. Now logs no more than once per 10 mins

[Jay Rolette]

Signed-off-by: Jay Rolette <rolette at infiniteio.com>
---
 lib/librte_kni/rte_kni.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
index fdb7509..f89319c 100644
--- a/lib/librte_kni/rte_kni.c
+++ b/lib/librte_kni/rte_kni.c
@@ -40,6 +40,7 @@
 #include <unistd.h>
 #include <sys/ioctl.h>
 
+#include <rte_cycles.h>
 #include <rte_spinlock.h>
 #include <rte_string_fns.h>
 #include <rte_ethdev.h>
@@ -61,6 +62,9 @@
 
 #define KNI_MEM_CHECK(cond) do { if (cond) goto kni_fail; } while (0)
 
+// Configure how often we log "out of memory" messages (in seconds)
+#define KNI_SPAM_SUPPRESSION_PERIOD 60*10
+
 /**
  * KNI context
  */
@@ -592,6 +596,10 @@ kni_free_mbufs(struct rte_kni *kni)
 static void
 kni_allocate_mbufs(struct rte_kni *kni)
 {
+	static uint64_t no_mbufs = 0;
+	static uint64_t spam_filter = 0;
+	static uint64_t delayPeriod = 0;
+
 	int i, ret;
 	struct rte_mbuf *pkts[MAX_MBUF_BURST_NUM];
 
@@ -620,7 +628,18 @@ kni_allocate_mbufs(struct rte_kni *kni)
 		pkts[i] = rte_pktmbuf_alloc(kni->pktmbuf_pool);
 		if (unlikely(pkts[i] == NULL)) {
 			/* Out of memory */
-			RTE_LOG(ERR, KNI, "Out of memory\n");
+			no_mbufs++;
+
+			// Memory leak or need to tune? Regardless, if we get here once,
+			// we will get here a *lot*. Don't spam the logs!
+			now = rte_get_tsc_cycles();
+			if (!delayPeriod)
+			    delayPeriod = rte_get_tsc_hz() * KNI_SPAM_SUPPRESSION_PERIOD;
+
+			if (!spam_filter || (now - spam_filter) > delayPeriod) {
+				RTE_LOG(ERR, KNI, "No mbufs available (%llu)\n", (unsigned long long)no_mbufs);
+				spam_filter = now;
+			}
 			break;
 		}
 	}
-- 
1.9.3 (Apple Git-50)