From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [PATCH v2] net/kni: calc mbuf&mtu according to given mb_pool Date: Thu, 14 Mar 2019 09:28:07 +0000 Message-ID: References: <1550738855-11107-1-git-send-email-lironh@marvell.com> <1550952885-2395-1-git-send-email-lironh@marvell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "dev@dpdk.org" , Alan Winkowski To: Liron Himi Return-path: Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by dpdk.org (Postfix) with ESMTP id CFEA1239 for ; Thu, 14 Mar 2019 10:28:10 +0100 (CET) In-Reply-To: Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 3/14/2019 6:37 AM, Liron Himi wrote: > > > -----Original Message----- > From: Ferruh Yigit > Sent: Wednesday, March 13, 2019 18:58 > To: Liron Himi > Cc: dev@dpdk.org; Alan Winkowski > Subject: Re: [PATCH v2] net/kni: calc mbuf&mtu according to given mb_pool > > On 3/10/2019 2:27 PM, Liron Himi wrote: >> Adding Alan. >> >> -----Original Message----- >> From: Liron Himi >> Sent: Monday, February 25, 2019 13:30 >> To: ferruh.yigit@intel.com >> Cc: dev@dpdk.org; Liron Himi ; Liron Himi >> >> Subject: RE: [PATCH v2] net/kni: calc mbuf&mtu according to given >> mb_pool >> >> Hi, >> >> Kind reminder > > Sorry for late response. > >> >> Regards, >> Liron >> >> -----Original Message----- >> From: lironh@marvell.com >> Sent: Saturday, February 23, 2019 22:15 >> To: ferruh.yigit@intel.com >> Cc: dev@dpdk.org; Liron Himi >> Subject: [PATCH v2] net/kni: calc mbuf&mtu according to given mb_pool >> >> From: Liron Himi >> >> - mbuf_size and mtu are now being calculated according to the given mb-pool. > > +1 to have dynamic size instead of fixed "MAX_PACKET_SZ" > >> >> - max_mtu is now being set according to the given mtu >> >> the above two changes provide the ability to work with jumbo frames > > From kernel -> userspace, if the data length is bigger than mbuf->buffer_len (- > headroom) the packet is dropped. I guess you are trying to solve that issue? > [L.H.] correct > > By providing larger mbuf buffer, it should be possible to send larger (jumbo) packets? > [L.H.] correct > > Another option can be adding multi segment send support, that also lets sending large packets from kernel to userspace, and it can co-exits with your patch. > What do you think, can you work on that support? > [L.H.] I suggest to first go with this patch, and then prepare multi-segment patch if possible Yes, I was hoping both can go in a same patchset, can it be possible? > Multi segment support already exists in userspace to kernel path, but otherway around is missing. > >> >> Signed-off-by: Liron Himi >> --- >> drivers/net/kni/rte_eth_kni.c | 10 +++++++--- >> kernel/linux/kni/compat.h | 4 ++++ >> kernel/linux/kni/kni_misc.c | 3 +++ > > It can be good to update release notes / kni documentation to document new feature. > [L.H.] okay > >> 3 files changed, 14 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/net/kni/rte_eth_kni.c >> b/drivers/net/kni/rte_eth_kni.c index a1e9970..5e02224 100644 >> --- a/drivers/net/kni/rte_eth_kni.c >> +++ b/drivers/net/kni/rte_eth_kni.c >> @@ -16,9 +16,11 @@ >> /* Only single queue supported */ >> #define KNI_MAX_QUEUE_PER_PORT 1 >> >> -#define MAX_PACKET_SZ 2048 >> #define MAX_KNI_PORTS 8 >> >> +#define KNI_ETHER_MTU(mbuf_size) \ >> + ((mbuf_size) - ETHER_HDR_LEN) /**< Ethernet MTU. */ >> + >> #define ETH_KNI_NO_REQUEST_THREAD_ARG "no_request_thread" >> static const char * const valid_arguments[] = { >> ETH_KNI_NO_REQUEST_THREAD_ARG, >> @@ -123,11 +125,13 @@ eth_kni_start(struct rte_eth_dev *dev) >> struct rte_kni_conf conf; >> const char *name = dev->device->name + 4; /* remove net_ */ >> >> + mb_pool = internals->rx_queues[0].mb_pool; >> snprintf(conf.name, RTE_KNI_NAMESIZE, "%s", name); >> conf.force_bind = 0; >> conf.group_id = port_id; >> - conf.mbuf_size = MAX_PACKET_SZ; >> - mb_pool = internals->rx_queues[0].mb_pool; >> + conf.mbuf_size = >> + rte_pktmbuf_data_room_size(mb_pool) - RTE_PKTMBUF_HEADROOM; >> + conf.mtu = KNI_ETHER_MTU(conf.mbuf_size); > > Can you please do "conf.mbuf_size" changes also to kni sample application? > kni sample application gets mtu from physical device, so I believe better to not change that but I think mbuf_size can be dynamic instead of hardcoded. > [L.H.] okay > > Another question, for the case mbuf size < ETHER_MTU, should we keep MTU ETHER_MTU, what do you think? > [L.H.] in any case we need to set the MTU according to the mbuf-size until multi-segment support will be available, right? Right. > >> >> internals->kni = rte_kni_alloc(mb_pool, &conf, NULL); >> if (internals->kni == NULL) { >> diff --git a/kernel/linux/kni/compat.h b/kernel/linux/kni/compat.h >> index 3c575c7..b9f9a6f 100644 >> --- a/kernel/linux/kni/compat.h >> +++ b/kernel/linux/kni/compat.h >> @@ -117,3 +117,7 @@ >> #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0) #define >> HAVE_SIGNAL_FUNCTIONS_OWN_HEADER #endif >> + >> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0) #define >> +HAVE_MAX_MTU_PARAM #endif >> diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c >> index 522ae23..04c78eb 100644 >> --- a/kernel/linux/kni/kni_misc.c >> +++ b/kernel/linux/kni/kni_misc.c >> @@ -459,6 +459,9 @@ kni_ioctl_create(struct net *net, uint32_t >> ioctl_num, >> >> if (dev_info.mtu) >> net_dev->mtu = dev_info.mtu; >> +#ifdef HAVE_MAX_MTU_PARAM >> + net_dev->max_mtu = net_dev->mtu; >> +#endif > > Do we need to set 'max_mtu'? I guess this is not really required for large packet support, if so what do you think making this separate patch? > [L.H.] 'max_mtu' is set by default to '1500', so in order to be able to modify the interface MTU to support jumbo (or even any size > 1500) the 'max_mtu' must be updated to the larger supported value. I missed that it set by default to '1500', I was thinking it is zero by default. Can you please point where its default value set in Linux?