diff --git a/Documentation/automake.mk b/Documentation/automake.mk index bc728dff315..24447949061 100644 --- a/Documentation/automake.mk +++ b/Documentation/automake.mk @@ -36,6 +36,7 @@ DOC_SOURCE = \ Documentation/topics/dpdk/index.rst \ Documentation/topics/dpdk/bridge.rst \ Documentation/topics/dpdk/jumbo-frames.rst \ + Documentation/topics/dpdk/memory.rst \ Documentation/topics/dpdk/pdump.rst \ Documentation/topics/dpdk/phy.rst \ Documentation/topics/dpdk/pmd.rst \ diff --git a/Documentation/intro/install/dpdk.rst b/Documentation/intro/install/dpdk.rst index 9e885ec5284..2468c641b08 100644 --- a/Documentation/intro/install/dpdk.rst +++ b/Documentation/intro/install/dpdk.rst @@ -170,6 +170,12 @@ Mount the hugepages, if not already mounted by default:: $ mount -t hugetlbfs none /dev/hugepages`` +.. note:: + + The amount of hugepage memory required can be affected by various + aspects of the datapath and device configuration. Refer to + :doc:`/topics/dpdk/memory` for more details. + .. _dpdk-vfio: Setup DPDK devices using VFIO diff --git a/Documentation/topics/dpdk/index.rst b/Documentation/topics/dpdk/index.rst index 181f61abbab..cf24a7b6d47 100644 --- a/Documentation/topics/dpdk/index.rst +++ b/Documentation/topics/dpdk/index.rst @@ -40,3 +40,4 @@ The DPDK Datapath /topics/dpdk/qos /topics/dpdk/pdump /topics/dpdk/jumbo-frames + /topics/dpdk/memory diff --git a/Documentation/topics/dpdk/memory.rst b/Documentation/topics/dpdk/memory.rst new file mode 100644 index 00000000000..e5fb166d5f2 --- /dev/null +++ b/Documentation/topics/dpdk/memory.rst @@ -0,0 +1,216 @@ +.. + Copyright (c) 2018 Intel Corporation + + Licensed under the Apache License, Version 2.0 (the "License"); you may + not use this file except in compliance with the License. You may obtain + a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + License for the specific language governing permissions and limitations + under the License. + + Convention for heading levels in Open vSwitch documentation: + + ======= Heading 0 (reserved for the title in a document) + ------- Heading 1 + ~~~~~~~ Heading 2 + +++++++ Heading 3 + ''''''' Heading 4 + + Avoid deeper levels because they do not render well. + +========================= +DPDK Device Memory Models +========================= + +DPDK device memory can be allocated in one of two ways in OVS DPDK, +**shared memory** or **per port memory**. The specifics of both are +detailed below. + +Shared Memory +------------- + +By default OVS DPDK uses a shared memory model. This means that multiple +ports can share the same mempool. For example when a port is added it will +have a given MTU and socket ID associated with it. If a mempool has been +created previously for an existing port that has the same MTU and socket ID, +that mempool is used for both ports. If there is no existing mempool +supporting these parameters then a new mempool is created. + +Per Port Memory +--------------- + +In the per port memory model, mempools are created per device and are not +shared. The benefit of this is a more transparent memory model where mempools +will not be exhausted by other DPDK devices. However this comes at a potential +increase in cost for memory dimensioning for a given deployment. Users should +be aware of the memory requirements for their deployment before using this +model and allocate the required hugepage memory. + +Per port mempool support may be enabled via a global config value, +```per-port-memory```. Setting this to true enables the per port memory +model for all DPDK devices in OVS:: + + $ ovs-vsctl set Open_vSwitch . other_config:per-port-memory=true + +.. important:: + + This value should be set before setting dpdk-init=true. If set after + dpdk-init=true then the daemon must be restarted to use per-port-memory. + +Calculating Memory Requirements +------------------------------- + +The amount of memory required for a given mempool can be calculated by the +**number mbufs in the mempool \* mbuf size**. + +Users should be aware of the following: + +* The **number of mbufs** per mempool will differ between memory models. + +* The **size of each mbuf** will be affected by the requested **MTU** size. + +.. important:: + + An mbuf size in bytes is always larger than the requested MTU size due to + alignment and rounding needed in OVS DPDK. + +Below are a number of examples of memory requirement calculations for both +shared and per port memory models. + +Shared Memory Calculations +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +In the shared memory model the number of mbufs requested is directly +affected by the requested MTU size as described in the table below. + ++--------------------+-------------+ +| MTU Size | Num MBUFS | ++====================+=============+ +| 1500 or greater | 262144 | ++--------------------+-------------+ +| Less than 1500 | 16384 | ++------------+-------+-------------+ + +.. Important:: + + If a deployment does not have enough memory to provide 262144 mbufs then + the requested amount is halved up until 16384. + +Example 1 ++++++++++ +:: + + MTU = 1500 Bytes + Number of mbufs = 262144 + Mbuf size = 3008 Bytes + Memory required = 262144 * 3008 = 788 MB + +Example 2 ++++++++++ +:: + + MTU = 1800 Bytes + Number of mbufs = 262144 + Mbuf size = 3008 Bytes + Memory required = 262144 * 3008 = 788 MB + +.. note:: + + Assuming the same socket is in use for example 1 and 2 the same mempool + would be shared. + +Example 3 ++++++++++ +:: + + MTU = 6000 Bytes + Number of mbufs = 262144 + Mbuf size = 8128 Bytes + Memory required = 262144 * 8128 = 2130 MB + +Example 4 ++++++++++ +:: + + MTU = 9000 Bytes + Number of mbufs = 262144 + Mbuf size = 10176 Bytes + Memory required = 262144 * 10176 = 2667 MB + +Per Port Memory Calculations +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The number of mbufs requested in the per port model is more complicated and +accounts for multiple dynamic factors in the datapath and device +configuration. + +A rough estimation of the number of mbufs required for a port is: +:: + + packets required to fill the device rxqs + + packets that could be stuck on other ports txqs + + packets on the pmd threads + + additional corner case memory. + +The algorithm in OVS used to calculate this is as follows: +:: + + requested number of rxqs * requested rxq size + + requested number of txqs * requested txq size + + min(RTE_MAX_LCORE, requested number of rxqs) * netdev_max_burst + + MIN_NB_MBUF. + +where: + +* **requested number of rxqs**: Number of requested receive queues for a + device. +* **requested rxq size**: The number of descriptors requested for a rx queue. +* **requested number of txqs**: Number of requested transmit queues for a + device. Calculated as the number of PMDs configured +1. +* **requested txq size**: the number of descriptors requested for a tx queue. +* **min(RTE_MAX_LCORE, requested number of rxqs)**: Compare the maximum + number of lcores supported by DPDK to the number of requested receive + queues for the device and use the variable of lesser value. +* **NETDEV_MAX_BURST**: Maximum number of of packets in a burst, defined as + 32. +* **MIN_NB_MBUF**: Additional memory for corner case, defined as 16384. + +For all examples below assume the following values: + +* requested_rxq_size = 2048 +* requested_txq_size = 2048 +* RTE_MAX_LCORE = 128 +* netdev_max_burst = 32 +* MIN_NB_MBUF = 16384 + +Example 1: (1 rxq, 1 PMD, 1500 MTU) ++++++++++++++++++++++++++++++++++++ +:: + + MTU = 1500 + Number of mbufs = (1 * 2048) + (2 * 2048) + (1 * 32) + (16384) = 22560 + Mbuf size = 3008 Bytes + Memory required = 22560 * 3008 = 67 MB + +Example 2: (1 rxq, 2 PMD, 6000 MTU) ++++++++++++++++++++++++++++++++++++ +:: + + MTU = 6000 + Number of mbufs = (1 * 2048) + (3 * 2048) + (1 * 32) + (16384) = 24608 + Mbuf size = 8128 Bytes + Memory required = 24608 * 8128 = 200 MB + +Example 3: (2 rxq, 2 PMD, 9000 MTU) ++++++++++++++++++++++++++++++++++++ +:: + + MTU = 9000 + Number of mbufs = (2 * 2048) + (3 * 2048) + (1 * 32) + (16384) = 26656 + Mbuf size = 10176 Bytes + Memory required = 26656 * 10176 = 271 MB diff --git a/NEWS b/NEWS index 74dca151660..b832cae7017 100644 --- a/NEWS +++ b/NEWS @@ -35,6 +35,7 @@ Post-v2.9.0 * Add LSC interrupt support for DPDK physical devices. * Allow init to fail and record DPDK status/version in OVS database. * Add experimental flow hardware offload support + * Support both shared and per port mempools for DPDK devices. - Userspace datapath: * Commands ovs-appctl dpif-netdev/pmd-*-show can now work on a single PMD * Detailed PMD performance metrics available with new command diff --git a/lib/dpdk-stub.c b/lib/dpdk-stub.c index 1df1c5848a3..1e0f46101d9 100644 --- a/lib/dpdk-stub.c +++ b/lib/dpdk-stub.c @@ -56,6 +56,12 @@ dpdk_vhost_iommu_enabled(void) return false; } +bool +dpdk_per_port_memory(void) +{ + return false; +} + void print_dpdk_version(void) { diff --git a/lib/dpdk.c b/lib/dpdk.c index 5c68ce430d6..0ee3e19c63b 100644 --- a/lib/dpdk.c +++ b/lib/dpdk.c @@ -48,6 +48,7 @@ static char *vhost_sock_dir = NULL; /* Location of vhost-user sockets */ static bool vhost_iommu_enabled = false; /* Status of vHost IOMMU support */ static bool dpdk_initialized = false; /* Indicates successful initialization * of DPDK. */ +static bool per_port_memory = false; /* Status of per port memory support */ static int process_vhost_flags(char *flag, const char *default_val, int size, @@ -384,6 +385,11 @@ dpdk_init__(const struct smap *ovs_other_config) VLOG_INFO("IOMMU support for vhost-user-client %s.", vhost_iommu_enabled ? "enabled" : "disabled"); + per_port_memory = smap_get_bool(ovs_other_config, + "per-port-memory", false); + VLOG_INFO("Per port memory for DPDK devices %s.", + per_port_memory ? "enabled" : "disabled"); + argv = grow_argv(&argv, 0, 1); argc = 1; argv[0] = xstrdup(ovs_get_program_name()); @@ -541,6 +547,12 @@ dpdk_vhost_iommu_enabled(void) return vhost_iommu_enabled; } +bool +dpdk_per_port_memory(void) +{ + return per_port_memory; +} + void dpdk_set_lcore_id(unsigned cpu) { diff --git a/lib/dpdk.h b/lib/dpdk.h index efdaa637c2b..bbb89d4e6f0 100644 --- a/lib/dpdk.h +++ b/lib/dpdk.h @@ -39,6 +39,7 @@ void dpdk_init(const struct smap *ovs_other_config); void dpdk_set_lcore_id(unsigned cpu); const char *dpdk_get_vhost_sock_dir(void); bool dpdk_vhost_iommu_enabled(void); +bool dpdk_per_port_memory(void); void print_dpdk_version(void); void dpdk_status(const struct ovsrec_open_vswitch *); #endif /* dpdk.h */ diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index 48e10f3cdc5..bb4d60f26cc 100644 --- a/lib/netdev-dpdk.c +++ b/lib/netdev-dpdk.c @@ -95,13 +95,24 @@ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20); #define NETDEV_DPDK_MBUF_ALIGN 1024 #define NETDEV_DPDK_MAX_PKT_LEN 9728 -/* Min number of packets in the mempool. OVS tries to allocate a mempool with - * roughly estimated number of mbufs: if this fails (because the system doesn't - * have enough hugepages) we keep halving the number until the allocation - * succeeds or we reach MIN_NB_MBUF */ +/* Max and min number of packets in the mempool. OVS tries to allocate a + * mempool with MAX_NB_MBUF: if this fails (because the system doesn't have + * enough hugepages) we keep halving the number until the allocation succeeds + * or we reach MIN_NB_MBUF */ + +#define MAX_NB_MBUF (4096 * 64) #define MIN_NB_MBUF (4096 * 4) #define MP_CACHE_SZ RTE_MEMPOOL_CACHE_MAX_SIZE +/* MAX_NB_MBUF can be divided by 2 many times, until MIN_NB_MBUF */ +BUILD_ASSERT_DECL(MAX_NB_MBUF % ROUND_DOWN_POW2(MAX_NB_MBUF / MIN_NB_MBUF) + == 0); + +/* The smallest possible NB_MBUF that we're going to try should be a multiple + * of MP_CACHE_SZ. This is advised by DPDK documentation. */ +BUILD_ASSERT_DECL((MAX_NB_MBUF / ROUND_DOWN_POW2(MAX_NB_MBUF / MIN_NB_MBUF)) + % MP_CACHE_SZ == 0); + /* * DPDK XSTATS Counter names definition */ @@ -312,12 +323,14 @@ static struct ovs_mutex dpdk_mp_mutex OVS_ACQ_AFTER(dpdk_mutex) = OVS_MUTEX_INITIALIZER; /* Contains all 'struct dpdk_mp's. */ -static struct ovs_list dpdk_mp_free_list OVS_GUARDED_BY(dpdk_mp_mutex) - = OVS_LIST_INITIALIZER(&dpdk_mp_free_list); +static struct ovs_list dpdk_mp_list OVS_GUARDED_BY(dpdk_mp_mutex) + = OVS_LIST_INITIALIZER(&dpdk_mp_list); -/* Wrapper for a mempool released but not yet freed. */ struct dpdk_mp { struct rte_mempool *mp; + int mtu; + int socket_id; + int refcount; struct ovs_list list_node OVS_GUARDED_BY(dpdk_mp_mutex); }; @@ -399,7 +412,7 @@ struct netdev_dpdk { PADDED_MEMBERS_CACHELINE_MARKER(CACHE_LINE_SIZE, cacheline1, struct ovs_mutex mutex OVS_ACQ_AFTER(dpdk_mutex); - struct rte_mempool *mp; + struct dpdk_mp *dpdk_mp; /* virtio identifier for vhost devices */ ovsrcu_index vid; @@ -565,68 +578,89 @@ dpdk_mp_full(const struct rte_mempool *mp) OVS_REQUIRES(dpdk_mp_mutex) /* Free unused mempools. */ static void -dpdk_mp_sweep(void) +dpdk_mp_sweep(void) OVS_REQUIRES(dpdk_mp_mutex) { struct dpdk_mp *dmp, *next; - ovs_mutex_lock(&dpdk_mp_mutex); - LIST_FOR_EACH_SAFE (dmp, next, list_node, &dpdk_mp_free_list) { - if (dpdk_mp_full(dmp->mp)) { + LIST_FOR_EACH_SAFE (dmp, next, list_node, &dpdk_mp_list) { + if (!dmp->refcount && dpdk_mp_full(dmp->mp)) { VLOG_DBG("Freeing mempool \"%s\"", dmp->mp->name); ovs_list_remove(&dmp->list_node); rte_mempool_free(dmp->mp); rte_free(dmp); } } - ovs_mutex_unlock(&dpdk_mp_mutex); } -/* Ensure a mempool will not be freed. */ -static void -dpdk_mp_do_not_free(struct rte_mempool *mp) OVS_REQUIRES(dpdk_mp_mutex) +/* Calculating the required number of mbufs differs depending on the + * mempool model being used. Check if per port memory is in use before + * calculating. + */ +static uint32_t +dpdk_calculate_mbufs(struct netdev_dpdk *dev, int mtu, bool per_port_mp) { - struct dpdk_mp *dmp, *next; + uint32_t n_mbufs; - LIST_FOR_EACH_SAFE (dmp, next, list_node, &dpdk_mp_free_list) { - if (dmp->mp == mp) { - VLOG_DBG("Removing mempool \"%s\" from free list", dmp->mp->name); - ovs_list_remove(&dmp->list_node); - rte_free(dmp); - break; + if (!per_port_mp) { + /* Shared memory are being used. + * XXX: this is a really rough method of provisioning memory. + * It's impossible to determine what the exact memory requirements are + * when the number of ports and rxqs that utilize a particular mempool + * can change dynamically at runtime. For now, use this rough + * heurisitic. + */ + if (mtu >= ETHER_MTU) { + n_mbufs = MAX_NB_MBUF; + } else { + n_mbufs = MIN_NB_MBUF; } + } else { + /* Per port memory is being used. + * XXX: rough estimation of number of mbufs required for this port: + * + * + + * + + * + + */ + n_mbufs = dev->requested_n_rxq * dev->requested_rxq_size + + dev->requested_n_txq * dev->requested_txq_size + + MIN(RTE_MAX_LCORE, dev->requested_n_rxq) * NETDEV_MAX_BURST + + MIN_NB_MBUF; } + + return n_mbufs; } -/* Returns a valid pointer when either of the following is true: - * - a new mempool was just created; - * - a matching mempool already exists. */ -static struct rte_mempool * -dpdk_mp_create(struct netdev_dpdk *dev, int mtu) +static struct dpdk_mp * +dpdk_mp_create(struct netdev_dpdk *dev, int mtu, bool per_port_mp) { char mp_name[RTE_MEMPOOL_NAMESIZE]; const char *netdev_name = netdev_get_name(&dev->up); int socket_id = dev->requested_socket_id; uint32_t n_mbufs; uint32_t hash = hash_string(netdev_name, 0); - struct rte_mempool *mp = NULL; + struct dpdk_mp *dmp = NULL; + int ret; - /* - * XXX: rough estimation of number of mbufs required for this port: - * - * + - * + - * + - */ - n_mbufs = dev->requested_n_rxq * dev->requested_rxq_size - + dev->requested_n_txq * dev->requested_txq_size - + MIN(RTE_MAX_LCORE, dev->requested_n_rxq) * NETDEV_MAX_BURST - + MIN_NB_MBUF; + dmp = dpdk_rte_mzalloc(sizeof *dmp); + if (!dmp) { + return NULL; + } + dmp->socket_id = socket_id; + dmp->mtu = mtu; + dmp->refcount = 1; + + n_mbufs = dpdk_calculate_mbufs(dev, mtu, per_port_mp); - ovs_mutex_lock(&dpdk_mp_mutex); do { /* Full DPDK memory pool name must be unique and cannot be - * longer than RTE_MEMPOOL_NAMESIZE. */ - int ret = snprintf(mp_name, RTE_MEMPOOL_NAMESIZE, + * longer than RTE_MEMPOOL_NAMESIZE. Note that for the shared + * mempool case this can result in one device using a mempool + * which references a different device in it's name. However as + * mempool names are hashed, the device name will not be readable + * so this is not an issue for tasks such as debugging. + */ + ret = snprintf(mp_name, RTE_MEMPOOL_NAMESIZE, "ovs%08x%02d%05d%07u", hash, socket_id, mtu, n_mbufs); if (ret < 0 || ret >= RTE_MEMPOOL_NAMESIZE) { @@ -642,96 +676,159 @@ dpdk_mp_create(struct netdev_dpdk *dev, int mtu) netdev_name, n_mbufs, socket_id, dev->requested_n_rxq, dev->requested_n_txq); - mp = rte_pktmbuf_pool_create(mp_name, n_mbufs, MP_CACHE_SZ, - sizeof (struct dp_packet) - sizeof (struct rte_mbuf), - MBUF_SIZE(mtu) - sizeof(struct dp_packet), socket_id); + dmp->mp = rte_pktmbuf_pool_create(mp_name, n_mbufs, + MP_CACHE_SZ, + sizeof (struct dp_packet) + - sizeof (struct rte_mbuf), + MBUF_SIZE(mtu) + - sizeof(struct dp_packet), + socket_id); - if (mp) { + if (dmp->mp) { VLOG_DBG("Allocated \"%s\" mempool with %u mbufs", mp_name, n_mbufs); /* rte_pktmbuf_pool_create has done some initialization of the - * rte_mbuf part of each dp_packet. Some OvS specific fields - * of the packet still need to be initialized by - * ovs_rte_pktmbuf_init. */ - rte_mempool_obj_iter(mp, ovs_rte_pktmbuf_init, NULL); + * rte_mbuf part of each dp_packet, while ovs_rte_pktmbuf_init + * initializes some OVS specific fields of dp_packet. + */ + rte_mempool_obj_iter(dmp->mp, ovs_rte_pktmbuf_init, NULL); + return dmp; } else if (rte_errno == EEXIST) { /* A mempool with the same name already exists. We just * retrieve its pointer to be returned to the caller. */ - mp = rte_mempool_lookup(mp_name); + dmp->mp = rte_mempool_lookup(mp_name); /* As the mempool create returned EEXIST we can expect the * lookup has returned a valid pointer. If for some reason * that's not the case we keep track of it. */ VLOG_DBG("A mempool with name \"%s\" already exists at %p.", - mp_name, mp); - /* Ensure this reused mempool will not be freed. */ - dpdk_mp_do_not_free(mp); + mp_name, dmp->mp); + return dmp; } else { - VLOG_ERR("Failed mempool \"%s\" create request of %u mbufs", - mp_name, n_mbufs); + VLOG_DBG("Failed to create mempool \"%s\" with a request of " + "%u mbufs, retrying with %u mbufs", + mp_name, n_mbufs, n_mbufs / 2); } - } while (!mp && rte_errno == ENOMEM && (n_mbufs /= 2) >= MIN_NB_MBUF); + } while (!dmp->mp && rte_errno == ENOMEM && (n_mbufs /= 2) >= MIN_NB_MBUF); - ovs_mutex_unlock(&dpdk_mp_mutex); - return mp; + VLOG_ERR("Failed to create mempool \"%s\" with a request of %u mbufs", + mp_name, n_mbufs); + + rte_free(dmp); + return NULL; } -/* Release an existing mempool. */ -static void -dpdk_mp_release(struct rte_mempool *mp) +static struct dpdk_mp * +dpdk_mp_get(struct netdev_dpdk *dev, int mtu, bool per_port_mp) { - if (!mp) { - return; - } + struct dpdk_mp *dmp, *next; + bool reuse = false; ovs_mutex_lock(&dpdk_mp_mutex); - if (dpdk_mp_full(mp)) { - VLOG_DBG("Freeing mempool \"%s\"", mp->name); - rte_mempool_free(mp); - } else { - struct dpdk_mp *dmp; + /* Check if shared memory is being used, if so check existing mempools + * to see if reuse is possible. */ + if (!per_port_mp) { + LIST_FOR_EACH (dmp, list_node, &dpdk_mp_list) { + if (dmp->socket_id == dev->requested_socket_id + && dmp->mtu == mtu) { + VLOG_DBG("Reusing mempool \"%s\"", dmp->mp->name); + dmp->refcount++; + reuse = true; + break; + } + } + } + /* Sweep mempools after reuse or before create. */ + dpdk_mp_sweep(); - dmp = dpdk_rte_mzalloc(sizeof *dmp); + if (!reuse) { + dmp = dpdk_mp_create(dev, mtu, per_port_mp); if (dmp) { - dmp->mp = mp; - ovs_list_push_back(&dpdk_mp_free_list, &dmp->list_node); + /* Shared memory will hit the reuse case above so will not + * request a mempool that already exists but we need to check + * for the EEXIST case for per port memory case. Compare the + * mempool returned by dmp to each entry in dpdk_mp_list. If a + * match is found, free dmp as a new entry is not required, set + * dmp to point to the existing entry and increment the refcount + * to avoid being freed at a later stage. + */ + if (per_port_mp && rte_errno == EEXIST) { + LIST_FOR_EACH (next, list_node, &dpdk_mp_list) { + if (dmp->mp == next->mp) { + rte_free(dmp); + dmp = next; + dmp->refcount++; + } + } + } else { + ovs_list_push_back(&dpdk_mp_list, &dmp->list_node); + } } } + + + ovs_mutex_unlock(&dpdk_mp_mutex); + + return dmp; +} + +/* Decrement reference to a mempool. */ +static void +dpdk_mp_put(struct dpdk_mp *dmp) +{ + if (!dmp) { + return; + } + + ovs_mutex_lock(&dpdk_mp_mutex); + ovs_assert(dmp->refcount); + dmp->refcount--; ovs_mutex_unlock(&dpdk_mp_mutex); } -/* Tries to allocate a new mempool - or re-use an existing one where - * appropriate - on requested_socket_id with a size determined by - * requested_mtu and requested Rx/Tx queues. - * On success - or when re-using an existing mempool - the new configuration - * will be applied. +/* Depending on the memory model being used this function tries to + * identify and reuse an existing mempool or tries to allocate a new + * mempool on requested_socket_id with mbuf size corresponding to the + * requested_mtu. On success, a new configuration will be applied. * On error, device will be left unchanged. */ static int netdev_dpdk_mempool_configure(struct netdev_dpdk *dev) OVS_REQUIRES(dev->mutex) { uint32_t buf_size = dpdk_buf_size(dev->requested_mtu); - struct rte_mempool *mp; + struct dpdk_mp *dmp; int ret = 0; + bool per_port_mp = dpdk_per_port_memory(); - dpdk_mp_sweep(); + /* With shared memory we do not need to configure a mempool if the MTU + * and socket ID have not changed, the previous configuration is still + * valid so return 0 */ + if (!per_port_mp && dev->mtu == dev->requested_mtu + && dev->socket_id == dev->requested_socket_id) { + return ret; + } - mp = dpdk_mp_create(dev, FRAME_LEN_TO_MTU(buf_size)); - if (!mp) { + dmp = dpdk_mp_get(dev, FRAME_LEN_TO_MTU(buf_size), per_port_mp); + if (!dmp) { VLOG_ERR("Failed to create memory pool for netdev " "%s, with MTU %d on socket %d: %s\n", dev->up.name, dev->requested_mtu, dev->requested_socket_id, rte_strerror(rte_errno)); ret = rte_errno; } else { - /* If a new MTU was requested and its rounded value equals the one - * that is currently used, then the existing mempool is returned. */ - if (dev->mp != mp) { - /* A new mempool was created, release the previous one. */ - dpdk_mp_release(dev->mp); - } else { - ret = EEXIST; + /* Check for any pre-existing dpdk_mp for the device before accessing + * the associated mempool. + */ + if (dev->dpdk_mp != NULL) { + /* A new MTU was requested, decrement the reference count for the + * devices current dpdk_mp. This is required even if a pointer to + * same dpdk_mp is returned by dpdk_mp_get. The refcount for dmp + * has already been incremented by dpdk_mp_get at this stage so it + * must be decremented to keep an accurate refcount for the + * dpdk_mp. + */ + dpdk_mp_put(dev->dpdk_mp); } - dev->mp = mp; + dev->dpdk_mp = dmp; dev->mtu = dev->requested_mtu; dev->socket_id = dev->requested_socket_id; dev->max_packet_len = MTU_TO_FRAME_LEN(dev->mtu); @@ -870,7 +967,8 @@ dpdk_eth_dev_port_config(struct netdev_dpdk *dev, int n_rxq, int n_txq) for (i = 0; i < n_rxq; i++) { diag = rte_eth_rx_queue_setup(dev->port_id, i, dev->rxq_size, - dev->socket_id, NULL, dev->mp); + dev->socket_id, NULL, + dev->dpdk_mp->mp); if (diag) { VLOG_INFO("Interface %s unable to setup rxq(%d): %s", dev->up.name, i, rte_strerror(-diag)); @@ -965,7 +1063,7 @@ dpdk_eth_dev_init(struct netdev_dpdk *dev) memcpy(dev->hwaddr.ea, eth_addr.addr_bytes, ETH_ADDR_LEN); rte_eth_link_get_nowait(dev->port_id, &dev->link); - mbp_priv = rte_mempool_get_priv(dev->mp); + mbp_priv = rte_mempool_get_priv(dev->dpdk_mp->mp); dev->buf_size = mbp_priv->mbuf_data_room_size - RTE_PKTMBUF_HEADROOM; /* Get the Flow control configuration for DPDK-ETH */ @@ -1219,7 +1317,7 @@ common_destruct(struct netdev_dpdk *dev) OVS_EXCLUDED(dev->mutex) { rte_free(dev->tx_q); - dpdk_mp_release(dev->mp); + dpdk_mp_put(dev->dpdk_mp); ovs_list_remove(&dev->list_node); free(ovsrcu_get_protected(struct ingress_policer *, @@ -1972,7 +2070,7 @@ netdev_dpdk_vhost_rxq_recv(struct netdev_rxq *rxq, return EAGAIN; } - nb_rx = rte_vhost_dequeue_burst(vid, qid, dev->mp, + nb_rx = rte_vhost_dequeue_burst(vid, qid, dev->dpdk_mp->mp, (struct rte_mbuf **) batch->packets, NETDEV_MAX_BURST); if (!nb_rx) { @@ -2211,7 +2309,7 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct dp_packet_batch *batch) continue; } - pkts[txcnt] = rte_pktmbuf_alloc(dev->mp); + pkts[txcnt] = rte_pktmbuf_alloc(dev->dpdk_mp->mp); if (OVS_UNLIKELY(!pkts[txcnt])) { dropped += cnt - i; break; @@ -3090,7 +3188,7 @@ netdev_dpdk_get_mempool_info(struct unixctl_conn *conn, ovs_mutex_lock(&dev->mutex); ovs_mutex_lock(&dpdk_mp_mutex); - rte_mempool_dump(stream, dev->mp); + rte_mempool_dump(stream, dev->dpdk_mp->mp); ovs_mutex_unlock(&dpdk_mp_mutex); ovs_mutex_unlock(&dev->mutex); @@ -3787,7 +3885,7 @@ dpdk_vhost_reconfigure_helper(struct netdev_dpdk *dev) err = netdev_dpdk_mempool_configure(dev); if (!err) { - /* A new mempool was created. */ + /* A new mempool was created or re-used. */ netdev_change_seq_changed(&dev->up); } else if (err != EEXIST){ return err; diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml index 76094852d4e..2ada246bd47 100644 --- a/vswitchd/vswitch.xml +++ b/vswitchd/vswitch.xml @@ -360,6 +360,23 @@

+ +

+ By default OVS DPDK uses a shared memory model wherein devices + that have the same MTU and socket values can share the same + mempool. Setting this value to true changes this + behaviour. Per port memory allow DPDK devices to use private + memory per device. This can provide greater transparency as + regards memory usage but potentially at the cost of greater memory + requirements. +

+

+ Changing this value requires restarting the daemon if dpdk-init has + already been set to true. +

+ +