Thank you Hemant, I think there might be one issue left with the patch
though.
The alloc_q must initially be filled with mbufs before getting mbuf back
on the tx_q.
So the patch should allow rte_kni_rx_burst to check if alloc_q is empty.
If so, it should invoke kni_allocate_mbufs(kni, 0)
(to fill the alloc_q with MAX_MBUF_BURST_NUM mbufs)
The patch for rte_kni_rx_burst would then look like:
@@ -575,7 +575,7 @@ rte_kni_rx_burst(struct rte_kni *kni, struct
rte_mbuf **mbufs, unsigned num)
/* If buffers removed, allocate mbufs and then put them into
alloc_q */
if (ret)
- kni_allocate_mbufs(kni);
+ kni_allocate_mbufs(kni, ret);
+ else if (unlikely(kni->alloc_q->write == kni->alloc_q->read))
+ kni_allocate_mbufs(kni, 0);
Olivier.
On 25/02/15 11:48, Hemant Agrawal wrote:
> From: Hemant Agrawal <hemant at freescale.com>
>
> if any buffer is read from the tx_q, MAX_BURST buffers will be allocated and
> attempted to be added to to the alloc_q.
> This seems terribly inefficient and it also looks like the alloc_q will
> quickly fill to its maximum capacity. If the system buffers are low in
> number, it will reach "out of memory" situation.
>
> This patch allocates the number of buffers as many dequeued from tx_q.
>
> Signed-off-by: Hemant Agrawal <hemant at freescale.com>
> ---
> lib/librte_kni/rte_kni.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
> index 4e70fa0..4cf8e30 100644
> --- a/lib/librte_kni/rte_kni.c
> +++ b/lib/librte_kni/rte_kni.c
> @@ -128,7 +128,7 @@ struct rte_kni_memzone_pool {
>
>
> static void kni_free_mbufs(struct rte_kni *kni);
> -static void kni_allocate_mbufs(struct rte_kni *kni);
> +static void kni_allocate_mbufs(struct rte_kni *kni, int num);
>
> static volatile int kni_fd = -1;
> static struct rte_kni_memzone_pool kni_memzone_pool = {
> @@ -575,7 +575,7 @@ rte_kni_rx_burst(struct rte_kni *kni, struct rte_mbuf
> **mbufs, unsigned num)
>
> /* If buffers removed, allocate mbufs and then put them into alloc_q */
> if (ret)
> - kni_allocate_mbufs(kni);
> + kni_allocate_mbufs(kni, ret);
>
> return ret;
> }
> @@ -594,7 +594,7 @@ kni_free_mbufs(struct rte_kni *kni)
> }
>
> static void
> -kni_allocate_mbufs(struct rte_kni *kni)
> +kni_allocate_mbufs(struct rte_kni *kni, int num)
> {
> int i, ret;
> struct rte_mbuf *pkts[MAX_MBUF_BURST_NUM];
> @@ -620,7 +620,10 @@ kni_allocate_mbufs(struct rte_kni *kni)
> return;
> }
>
> - for (i = 0; i < MAX_MBUF_BURST_NUM; i++) {
> + if (num == 0 || num > MAX_MBUF_BURST_NUM)
> + num = MAX_MBUF_BURST_NUM;
> +
> + for (i = 0; i < num; i++) {
> pkts[i] = rte_pktmbuf_alloc(kni->pktmbuf_pool);
> if (unlikely(pkts[i] == NULL)) {
> /* Out of memory */
> @@ -636,7 +639,7 @@ kni_allocate_mbufs(struct rte_kni *kni)
> ret = kni_fifo_put(kni->alloc_q, (void **)pkts, i);
>
> /* Check if any mbufs not put into alloc_q, and then free them */
> - if (ret >= 0 && ret < i && ret < MAX_MBUF_BURST_NUM) {MAX_MBUF_BURST_NUM
>
> + if (ret >= 0 && ret < i && ret < num) {
> int j;
>
> for (j = ret; j < i; j++)
--
*Olivier Dem?*
*Druid Software Ltd.*
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