From 49da4e82cf94a5b7d8fc611c2ca16433ef52881c Mon Sep 17 00:00:00 2001 From: Gowrishankar Muthukrishnan Date: Thu, 11 May 2017 17:21:26 +0530 Subject: [PATCH] kni: allocate no more mbuf than empty slots in queue In kni_allocate_mbufs(), we attempt to add max_burst (32) count of mbuf always into alloc_q, which is excessively leading too many rte_pktmbuf_ free() when alloc_q is contending at high packet rate (for eg 10Gig data). In a situation when alloc_q fifo can only accommodate very few (or zero) mbuf, create only what needed and add in fifo. With this patch, we could stop random network stall in KNI at higher packet rate (eg 1G or 10G data between vEth0 and PMD) sufficiently exhausting alloc_q on above condition. I tested i40e PMD for this purpose in ppc64le. Signed-off-by: Gowrishankar Muthukrishnan Acked-by: Ferruh Yigit --- lib/librte_kni/rte_kni.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c index 40288a179d..8c483c1f41 100644 --- a/lib/librte_kni/rte_kni.c +++ b/lib/librte_kni/rte_kni.c @@ -624,6 +624,7 @@ kni_allocate_mbufs(struct rte_kni *kni) int i, ret; struct rte_mbuf *pkts[MAX_MBUF_BURST_NUM]; void *phys[MAX_MBUF_BURST_NUM]; + int allocq_free; RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pool) != offsetof(struct rte_kni_mbuf, pool)); @@ -646,7 +647,9 @@ kni_allocate_mbufs(struct rte_kni *kni) return; } - for (i = 0; i < MAX_MBUF_BURST_NUM; i++) { + allocq_free = (kni->alloc_q->read - kni->alloc_q->write - 1) \ + & (MAX_MBUF_BURST_NUM - 1); + for (i = 0; i < allocq_free; i++) { pkts[i] = rte_pktmbuf_alloc(kni->pktmbuf_pool); if (unlikely(pkts[i] == NULL)) { /* Out of memory */ -- 2.20.1