From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olivier Deme Subject: Re: [PATCH] kni:optimization of rte_kni_rx_burst Date: Wed, 25 Feb 2015 12:13:42 +0000 Message-ID: <54EDBC76.2050507@druidsoftware.com> References: <14248648813214-git-send-email-Hemant@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable To: dev-VfR2kkLFssw@public.gmane.org Return-path: In-Reply-To: <14248648813214-git-send-email-Hemant-KZfg59tc24xl57MIdRCFDg@public.gmane.org> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" Thank you Hemant, I think there might be one issue left with the patch=20 though. The alloc_q must initially be filled with mbufs before getting mbuf back=20 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=20 rte_mbuf **mbufs, unsigned num) /* If buffers removed, allocate mbufs and then put them into=20 alloc_q */ if (ret) - kni_allocate_mbufs(kni); + kni_allocate_mbufs(kni, ret); + else if (unlikely(kni->alloc_q->write =3D=3D kni->alloc_q->read)) + kni_allocate_mbufs(kni, 0); Olivier. On 25/02/15 11:48, Hemant Agrawal wrote: > From: Hemant Agrawal > > if any buffer is read from the tx_q, MAX_BURST buffers will be allocate= d 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 n= umber, 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 > --- > 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 { > =20 > =20 > 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); > =20 > static volatile int kni_fd =3D -1; > static struct rte_kni_memzone_pool kni_memzone_pool =3D { > @@ -575,7 +575,7 @@ rte_kni_rx_burst(struct rte_kni *kni, struct rte_mb= uf **mbufs, unsigned num) > =20 > /* If buffers removed, allocate mbufs and then put them into alloc_q= */ > if (ret) > - kni_allocate_mbufs(kni); > + kni_allocate_mbufs(kni, ret); > =20 > return ret; > } > @@ -594,7 +594,7 @@ kni_free_mbufs(struct rte_kni *kni) > } > =20 > 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; > } > =20 > - for (i =3D 0; i < MAX_MBUF_BURST_NUM; i++) { > + if (num =3D=3D 0 || num > MAX_MBUF_BURST_NUM) > + num =3D MAX_MBUF_BURST_NUM; > + > + for (i =3D 0; i < num; i++) { > pkts[i] =3D rte_pktmbuf_alloc(kni->pktmbuf_pool); > if (unlikely(pkts[i] =3D=3D NULL)) { > /* Out of memory */ > @@ -636,7 +639,7 @@ kni_allocate_mbufs(struct rte_kni *kni) > ret =3D kni_fifo_put(kni->alloc_q, (void **)pkts, i); > =20 > /* Check if any mbufs not put into alloc_q, and then free them */ > - if (ret >=3D 0 && ret < i && ret < MAX_MBUF_BURST_NUM) {MAX_MBUF_BURS= T_NUM > > + if (ret >=3D 0 && ret < i && ret < num) { > int j; > =20 > for (j =3D ret; j < i; j++) --=20 *Olivier Dem=E9* *Druid Software Ltd.* *Tel: +353 1 202 1831* *Email: odeme-UsMDwKmwmRBx67MzidHQgQC/G2K4zDHf@public.gmane.org * *URL: http://www.druidsoftware.com* *Hall 7, stand 7F70.* Druid Software: Monetising enterprise small cells solutions.