From: wangyunjian <wangyunjian@huawei.com>
To: <dev@dpdk.org>
Cc: <ferruh.yigit@intel.com>, <thomas@monjalon.net>,
<gowrishankar.m@linux.vnet.ibm.com>, <dingxiaoxiong@huawei.com>,
Yunjian Wang <wangyunjian@huawei.com>, <stable@dpdk.org>,
Cheng Liu <liucheng11@huawei.com>
Subject: [dpdk-dev] [PATCH v3] kni: fix mbuf allocation for alloc FIFO
Date: Tue, 22 Jun 2021 20:44:29 +0800 [thread overview]
Message-ID: <1624365869-31872-1-git-send-email-wangyunjian@huawei.com> (raw)
In-Reply-To: <4aebf99afe5bae2b25f2e5445a32243ffd6f7e97.1624359204.git.wangyunjian@huawei.com>
From: Yunjian Wang <wangyunjian@huawei.com>
In kni_allocate_mbufs(), we alloc mbuf for alloc_q as this code.
allocq_free = (kni->alloc_q->read - kni->alloc_q->write - 1) \
& (MAX_MBUF_BURST_NUM - 1);
The value of allocq_free maybe zero, for example :
The ring size is 1024. After init, write = read = 0. Then we fill
kni->alloc_q to full. At this time, write = 1023, read = 0.
Then the kernel send 32 packets to userspace. At this time, write
= 1023, read = 32. And then the userspace receive this 32 packets.
Then fill the kni->alloc_q, (32 - 1023 - 1) & 31 = 0, fill nothing.
...
Then the kernel send 32 packets to userspace. At this time, write
= 1023, read = 992. And then the userspace receive this 32 packets.
Then fill the kni->alloc_q, (992 - 1023 - 1) & 31 = 0, fill nothing.
Then the kernel send 32 packets to userspace. The kni->alloc_q only
has 31 mbufs and will drop one packet.
Absolutely, this is a special scene. Normally, it will fill some
mbufs everytime, but may not enough for the kernel to use.
In this patch, we always keep the kni->alloc_q to full for the kernel
to use.
Fixes: 49da4e82cf94 ("kni: allocate no more mbuf than empty slots in queue")
Cc: stable@dpdk.org
Signed-off-by: Cheng Liu <liucheng11@huawei.com>
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
v3:
update patch title
v2:
add fixes tag and update commit log
---
lib/kni/rte_kni.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/kni/rte_kni.c b/lib/kni/rte_kni.c
index 9dae6a8d7c..eb24b0d0ae 100644
--- a/lib/kni/rte_kni.c
+++ b/lib/kni/rte_kni.c
@@ -677,8 +677,9 @@ kni_allocate_mbufs(struct rte_kni *kni)
return;
}
- allocq_free = (kni->alloc_q->read - kni->alloc_q->write - 1)
- & (MAX_MBUF_BURST_NUM - 1);
+ allocq_free = kni_fifo_free_count(kni->alloc_q);
+ allocq_free = (allocq_free > MAX_MBUF_BURST_NUM) ?
+ MAX_MBUF_BURST_NUM : allocq_free;
for (i = 0; i < allocq_free; i++) {
pkts[i] = rte_pktmbuf_alloc(kni->pktmbuf_pool);
if (unlikely(pkts[i] == NULL)) {
--
2.23.0
next prev parent reply other threads:[~2021-06-22 12:44 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-31 12:09 [dpdk-dev] [PATCH] kni: fix wrong mbuf alloc count in kni_allocate_mbufs wangyunjian
2021-06-18 13:37 ` Ferruh Yigit
2021-06-21 3:27 ` wangyunjian
2021-06-21 11:26 ` Ferruh Yigit
2021-06-22 7:32 ` wangyunjian
2021-06-22 7:43 ` Ferruh Yigit
2021-06-22 10:57 ` [dpdk-dev] [PATCH v2] " wangyunjian
2021-06-22 12:27 ` Ferruh Yigit
2021-06-22 12:32 ` wangyunjian
2021-06-22 12:44 ` wangyunjian [this message]
2021-06-22 20:46 ` [dpdk-dev] [dpdk-stable] [PATCH v3] kni: fix mbuf allocation for alloc FIFO Thomas Monjalon
2021-06-23 12:16 ` wangyunjian
2021-06-23 14:11 ` Ferruh Yigit
2021-06-23 14:41 ` Thomas Monjalon
2021-06-24 1:55 ` Ajit Khaparde
2021-06-24 7:43 ` Thomas Monjalon
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