> Hi Ian, > > Thanks for bringing this forward. > > I've tested this on current master by re-configuring MTUs of existing > ports, adding new ports, deleting existing ones, etc. It seems to be > behaving as expected: > - On the shared model, it allocates a new mempool only if the MTU changes, > otherwise reuses the already existing one. And it frees a mempool only if > it isn't being used by any port; > - On the per-port model, it allocates a new mempool for every port. And it > frees the mempools when the ports are destroyed / MTU is changed. > > There's a catch on how mempools are freed, though. I have a comment on > that in-line below*. > > (I see Kevin has sent a review as well, so I'll refrain to touch on the > same points, unless to re-iterate.)
Thanks for the review Tiago, comments inline. > > On 18/05/2018 15:30, Ian Stokes wrote: > > This commit re-introduces the concept of shared mempools as the > > default memory model for DPDK devices. Per port mempools are still > > available but must be enabled explicitly by a user. > > > > OVS previously used a shared mempool model for ports with the same MTU > > and socket configuration. This was replaced by a per port mempool > > model to address issues flagged by users such as: > > > > https://mail.openvswitch.org/pipermail/ovs-discuss/2016-September/0425 > > 60.html > > > > However the per port model potentially requires an increase in memory > > resource requirements to support the same number of ports and > > configuration as the shared port model. > > > > This is considered a blocking factor for current deployments of OVS > > when upgrading to future OVS releases as a user may have to > > redimension memory for the same deployment configuration. This may not > > be possible for users. > > > > This commit resolves the issue by re-introducing shared mempools as > > the default memory behaviour in OVS DPDK but also refactors the memory > > configuration code to allow for per port mempools. > > > > This patch adds a new global config option, per-port-mp-enabled, that > > controls the enablement of per port mempools for DPDK devices. > > > > ovs-vsctl set Open_vSwitch . other_config:per-port-mp-enabled=true > > > > This value defaults to false; to enable per port mempool support, this > > field should be set to true when setting other global parameters on > > init (such as "dpdk-socket-mem", for example). Changing the value at > > runtime is not supported, and requires restarting the vswitch daemon. > > > > The mempool sweep functionality is also replaced with the sweep > > functionality from OVS 2.9 found in commits > > > > c77f692 (netdev-dpdk: Free mempool only when no in-use mbufs.) > > a7fb0a4 (netdev-dpdk: Add mempool reuse/free debug.) > > > > As this patch is RFC there are a number of TO-DOs including adding a > > memory calculation section to the documentation for both models. This > > is expected to be completed in the v1 after RFC. > > > > Signed-off-by: Ian Stokes <ian.sto...@intel.com> > > --- > > Documentation/automake.mk | 1 + > > Documentation/topics/dpdk/index.rst | 1 + > > Documentation/topics/dpdk/memory.rst | 67 +++++++ > > NEWS | 1 + > > lib/dpdk-stub.c | 6 + > > lib/dpdk.c | 13 ++ > > lib/dpdk.h | 1 + > > lib/netdev-dpdk.c | 326 +++++++++++++++++++++------- > ------- > > vswitchd/vswitch.xml | 16 ++ > > 9 files changed, 305 insertions(+), 127 deletions(-) create mode > > 100644 Documentation/topics/dpdk/memory.rst > > > > diff --git a/Documentation/automake.mk b/Documentation/automake.mk > > index 683ca14..14c2189 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/topics/dpdk/index.rst > > b/Documentation/topics/dpdk/index.rst > > index 181f61a..cf24a7b 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 0000000..1198067 > > --- /dev/null > > +++ b/Documentation/topics/dpdk/memory.rst > > @@ -0,0 +1,67 @@ > > +.. > > + Copyright 2018, Intel, Inc. > > + > > + 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 mempools or per port mempools. The specifics of both are > > +detailed below. > > + > > +Shared Mempools > > +--------------- > > + > > +By Default OVS DPDK uses a shared mempool 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 Mempools > > +----------------- > > + > > +In the per port mempool 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-mp-enabled```. Setting this to true enables the per port > > +mempool model for all DPDK devices in OVS:: > > + > > + $ ovs-vsctl set Open_vSwitch . > > + other_config:per-port-mp-enabled=true > > + > > +.. important:: > > + > > + Changing this value requires restarting the daemon. > > + > > +.. todo:: > > + > > + Add memory calculation section for both mempool models. > > diff --git a/NEWS b/NEWS > > index ec548b0..c9991cf 100644 > > --- a/NEWS > > +++ b/NEWS > > @@ -30,6 +30,7 @@ Post-v2.9.0 > > * New 'check-dpdk' Makefile target to run a new system testsuite. > > See Testing topic for the details. > > * Add LSC interrupt support for DPDK physical devices. > > + * 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 041cd0c..d2a9718 > > 100644 > > --- a/lib/dpdk-stub.c > > +++ b/lib/dpdk-stub.c > > @@ -55,6 +55,12 @@ dpdk_vhost_iommu_enabled(void) > > return false; > > } > > > > +bool > > +dpdk_per_port_mempool_enabled(void) > > +{ > > + return false; > > +} > > + > > void > > print_dpdk_version(void) > > { > > diff --git a/lib/dpdk.c b/lib/dpdk.c > > index 00dd974..e251970 100644 > > --- a/lib/dpdk.c > > +++ b/lib/dpdk.c > > @@ -43,6 +43,8 @@ static FILE *log_stream = NULL; /* Stream for > DPDK log redirection */ > > > > static char *vhost_sock_dir = NULL; /* Location of vhost-user sockets > */ > > static bool vhost_iommu_enabled = false; /* Status of vHost IOMMU > > support */ > > +static bool per_port_mp_enabled = false; /* Status of per port mempool > > + * support */ > > > > static int > > process_vhost_flags(char *flag, const char *default_val, int size, @@ > > -354,6 +356,11 @@ dpdk_init__(const struct smap *ovs_other_config) > > VLOG_INFO("IOMMU support for vhost-user-client %s.", > > vhost_iommu_enabled ? "enabled" : "disabled"); > > > > + per_port_mp_enabled = smap_get_bool(ovs_other_config, > > + "per-port-mp-enabled", false); > > + VLOG_INFO("Per port mempool for DPDK devices %s.", > > + per_port_mp_enabled ? "enabled" : "disabled"); > > + > > argv = grow_argv(&argv, 0, 1); > > argc = 1; > > argv[0] = xstrdup(ovs_get_program_name()); @@ -498,6 +505,12 @@ > > dpdk_vhost_iommu_enabled(void) > > return vhost_iommu_enabled; > > } > > > > +bool > > +dpdk_per_port_mempool_enabled(void) > > +{ > > + return per_port_mp_enabled; > > +} > > + > > void > > dpdk_set_lcore_id(unsigned cpu) > > { > > diff --git a/lib/dpdk.h b/lib/dpdk.h > > index b041535..243385c 100644 > > --- a/lib/dpdk.h > > +++ b/lib/dpdk.h > > @@ -38,6 +38,7 @@ 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_mempool_enabled(void); > > void print_dpdk_version(void); > > > > #endif /* dpdk.h */ > > diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index > > 87152a7..cda2ace 100644 > > --- a/lib/netdev-dpdk.c > > +++ b/lib/netdev-dpdk.c > > @@ -91,13 +91,24 @@ 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 > > */ > > @@ -296,13 +307,14 @@ static struct ovs_list dpdk_list > > OVS_GUARDED_BY(dpdk_mutex) 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); > > }; > > > > @@ -381,7 +393,7 @@ 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; > > @@ -526,88 +538,70 @@ ovs_rte_pktmbuf_init(struct rte_mempool *mp > OVS_UNUSED, > > dp_packet_init_dpdk((struct dp_packet *) pkt, pkt->buf_len); } > > > > -static int > > -dpdk_mp_full(const struct rte_mempool *mp) > > OVS_REQUIRES(dpdk_mp_mutex) -{ > > - unsigned ring_count; > > - /* This logic is needed because rte_mempool_full() is not > guaranteed to > > - * be atomic and mbufs could be moved from mempool cache --> > mempool ring > > - * during the call. However, as no mbufs will be taken from the > mempool > > - * at this time, we can work around it by also checking the ring > entries > > - * separately and ensuring that they have not changed. > > - */ > > - ring_count = rte_mempool_ops_get_count(mp); > > - if (rte_mempool_full(mp) && rte_mempool_ops_get_count(mp) == > ring_count) { > > - return 1; > > - } > > - > > - return 0; > > -} > > - > > -/* Free unused mempools. */ > > -static void > > -dpdk_mp_sweep(void) > > +/* Calculating the required number of mbufs differs depending on the > > + * mempool model being used. Check if per port mempools are 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; > > > > - ovs_mutex_lock(&dpdk_mp_mutex); > > - LIST_FOR_EACH_SAFE (dmp, next, list_node, &dpdk_mp_free_list) { > > - if (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); > > + if (!per_port_mp) { > > + /* Shared mempools 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; > > Is this going to be configurable in the future? > So this has been raised before, the general feedback was that it becomes another tunable knob for OVS DPDK that users may not be aware of or how to adjust best for based on their deployments. For usability purposes it has been hard coded to date without much issue. > > + } else { > > + n_mbufs = MIN_NB_MBUF; > > } > > + } else { > > + /* Per port mempools are being used. > > + * XXX: rough estimation of number of mbufs required for this > port: > > + * <packets required to fill the device rxqs> > > + * + <packets that could be stuck on other ports txqs> > > + * + <packets in the pmd threads> > > + * + <additional memory for corner cases> > > + */ > > + 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; > > } > > - 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) -{ > > - struct dpdk_mp *dmp, *next; > > > > - 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; > > - } > > - } > > + 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; > > - > > - /* > > - * XXX: rough estimation of number of mbufs required for this port: > > - * <packets required to fill the device rxqs> > > - * + <packets that could be stuck on other ports txqs> > > - * + <packets in the pmd threads> > > - * + <additional memory for corner cases> > > - */ > > - 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; > > + struct dpdk_mp *dmp = NULL; > > + int ret; > > + > > + 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, > > + 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) { @@ -623,102 > > +617,179 @@ 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); > > } else { > > VLOG_ERR("Failed mempool \"%s\" create request of %u > mbufs", > > mp_name, n_mbufs); > > } > > Just a thought, but now with shared memory where n_mbufs are initially set > to 4096*64, one can see this error log printed a few times before the > memory gets allocated. We could potentially demote this to a WARN and > write a more friendly message and only print the error below, before > returning to the caller (at that point we surely couldn't allocate the > mempool). Sure, good idea as discussed in another thread by Kevin, I think we can change it to debug altogether. > > > - } 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; > > + rte_free(dmp); > > + return NULL; > > } > > > > -/* Release an existing mempool. */ > > +static int > > +dpdk_mp_full(const struct rte_mempool *mp) > > +OVS_REQUIRES(dpdk_mp_mutex) { > > + unsigned ring_count; > > + /* This logic is needed because rte_mempool_full() is not > guaranteed to > > + * be atomic and mbufs could be moved from mempool cache --> > mempool ring > > + * during the call. However, as no mbufs will be taken from the > mempool > > + * at this time, we can work around it by also checking the ring > entries > > + * separately and ensuring that they have not changed. > > + */ > > + ring_count = rte_mempool_ops_get_count(mp); > > + if (rte_mempool_full(mp) && rte_mempool_ops_get_count(mp) == > ring_count) { > > + return 1; > > + } > > + > > + return 0; > > +} > > + > > +/* Free unused mempools. */ > > static void > > -dpdk_mp_release(struct rte_mempool *mp) > > +dpdk_mp_sweep(void) OVS_REQUIRES(dpdk_mp_mutex) > > { > > - if (!mp) { > > - return; > > + struct dpdk_mp *dmp, *next; > > + > > + 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); > > + } > > } > > +} > > + > > +static struct dpdk_mp * > > +dpdk_mp_get(struct netdev_dpdk *dev, int mtu, bool per_port_mp) { > > + struct dpdk_mp *dmp; > > + 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 mempools are 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(); > > *Should dpdk_mp_sweep() be called when destroying an interface as well, in > common_destruct()? While testing, I've noticed that if I add one port and > delete the same port the mempool will still be allocated until you add > another port, since dpdk_mp_sweep() will only be called on the next call > to dpdp_mp_get(). This could potentially create problems in the per-port > model where one deletes a certain number of ports and can't add any other > ports because there's (hanging) mempools holding memory. > I can look into this in the next revision to handle this better if required, as discussed on separate threads it could be the case where it's preffered to defer as long as possible. The per port model is typically used in a more dynamic environment where changes occur (port add/deletes) quite often so we could look to sweep if it makes sense in common destruct then. > > > > - 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); > > + ovs_list_push_back(&dpdk_mp_list, &dmp->list_node); > > } > > } > > + > > ovs_mutex_unlock(&dpdk_mp_mutex); > > + > > + return dmp; > > } > > > > -/* 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. > > +/* 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); } > > + > > +/* Depending on the memory model being used this function tries > > + * identify and reuse an existing mempool or tries to allocate new > > + * mempool on requested_socket_id with mbuf size corresponding to > > + * requested_mtu. On success 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 *mp; > > int ret = 0; > > + bool per_port_mp = dpdk_per_port_mempool_enabled(); > > > > - dpdk_mp_sweep(); > > + /* With shared mempools 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 (dev->mtu == dev->requested_mtu > > + && dev->socket_id == dev->requested_socket_id > > + && (!per_port_mp)) { > > I also find that moving the `(!per_port_mp)` condition to the beginning > improves readability here. It even goes in hand with your comment just > above - "With shared mempools we do not ...". > > > + return ret; > > + } > > > > - mp = dpdk_mp_create(dev, FRAME_LEN_TO_MTU(buf_size)); > > + mp = dpdk_mp_get(dev, FRAME_LEN_TO_MTU(buf_size), per_port_mp); > > if (!mp) { > > 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; > > + rte_strerror(rte_errno)); > > Missing indentation here. > Will fix in the v2. > > + return 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 */ > > + if (dev->dpdk_mp != NULL) { > > + /* 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->dpdk_mp->mp != mp->mp) { > > + /* A new mempool was created, release the previous one. > */ > > + dpdk_mp_put(dev->dpdk_mp); > > + } else { > > + /* If the mempool already exists in the current dpdk_mp > then > > + * we need to ensure dpdk_mp that was just created is > freed in > > + * the next sweep as it will not be used. */ > The code path around the `else` block here will only be called when > `!per_port_mp`. This is because `dpdk_mp_get()` will only return an > already existing mempool when using the shared model. Otherwise a new one > is always returned, and thus the `if (dev->dpdk_mp->mp != mp->mp)` will be > true. Am I reading this right? If so then refactoring this a bit to > differentiate on `per_port_mp` might help on readability - this goes in- > line with Kevin's comment about making this piece a bit more readable. > > On the same note, the comment above mislead me to think that the allocated > `mp` is being freed, which would result in error since the same `mp` is > then assigned below. Instead, what it is doing is decrementing the > refcount in struct dpdk_mp, which might end up being freed on the next > dpdk_mp_sweep() if `refcount=0`. But that won't happen on the shared model > unless no port is using the mempool. > After looking ver the ongoing thread as regards this code block, it's bugs and can be simplified by doing more work around the EEXIST error at the create_mp function, it it would also help avoid using the dpdk_mp_list for dpdk_mps that will be freed anyway due to the mempool already being available. Thanks Ian > Thanks, > Tiago. > > > > + dpdk_mp_put(mp); > > + ret = EEXIST; > > + } > > } > > - dev->mp = mp; > > + dev->dpdk_mp = mp; > > dev->mtu = dev->requested_mtu; > > dev->socket_id = dev->requested_socket_id; > > dev->max_packet_len = MTU_TO_FRAME_LEN(dev->mtu); > > } > > > > - return ret; > > + return 0; > > } > > > > static void > > @@ -835,7 +906,8 @@ 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)); @@ > > -922,7 +994,7 @@ 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 */ @@ -1176,7 > > +1248,7 @@ 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 *, @@ -1928,7 > > +2000,7 @@ 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) { > > @@ -2167,7 +2239,7 @@ 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; > > @@ -3047,7 +3119,7 @@ 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); @@ -3742,7 +3814,7 @@ > > 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 > > 7ab90d5..95520af 100644 > > --- a/vswitchd/vswitch.xml > > +++ b/vswitchd/vswitch.xml > > @@ -359,6 +359,22 @@ > > </p> > > </column> > > > > + <column name="other_config" key="per-port-mp-enabled" > > + type='{"type": "boolean"}'> > > + <p> > > + By default OVS DPDK uses a shared mempool memory model > wherein > > + devices that have the same MTU and socket values can share > the same > > + mempool. Setting this value to <code>true</code> changes this > > + behaviour. Per port mempools allow DPDK devices to use a > private > > + mempool per device. This can provide greater transapraency as > > + regards memory usage but potentially at the cost of greater > memory > > + requirements. > > + </p> > > + <p> > > + Changing this value requires restarting the daemon. > > + </p> > > + </column> > > + > > <column name="other_config" key="tx-flush-interval" > > type='{"type": "integer", > > "minInteger": 0, "maxInteger": 1000000}'> > > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
