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: Fri, 15 Mar 2019 17:59:04 +0000 Message-ID: <5986e455-d6f4-8f66-d1c0-4e3293ef1769@intel.com> 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 mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id E9B2A4C95 for ; Fri, 15 Mar 2019 18:59:06 +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 3/15/2019 5:02 PM, Liron Himi wrote: > > > -----Original Message----- > From: Ferruh Yigit > Sent: Thursday, March 14, 2019 11:28 > To: Liron Himi > Cc: dev@dpdk.org; Alan Winkowski > Subject: Re: [PATCH v2] net/kni: calc mbuf&mtu according to given mb_pool > > On 3/14/2019 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? > [L.H.] I'm on tight schedule right now, I prefer to continue with this patch as is, multi-segment support can be pushed later on. OK > >> 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? > [L.H.] I also thought that a zero value will make more sense to provide backwards compatibility, but this is not the case. > Here is the code snipped from net/ethernet/eth.c : > void ether_setup(struct net_device *dev) > { > dev->header_ops = ð_header_ops; > dev->type = ARPHRD_ETHER; > dev->hard_header_len = ETH_HLEN; > dev->min_header_len = ETH_HLEN; > dev->mtu = ETH_DATA_LEN; > dev->min_mtu = ETH_MIN_MTU; > dev->max_mtu = ETH_DATA_LEN; > You are right, thanks for the pointer, please go with this update.