[ovs-dev] [PATCH v4] netdev-dpdk: Create separate memory pool for each port.
antonio.fischetti at intel.com
antonio.fischetti at intel.com
Fri Aug 25 10:09:12 UTC 2017
Since it's possible to delete memory pool in DPDK
we can try to estimate better required memory size
when port is reconfigured, e.g. with different number
of rx queues.
CC: Kevin Traynor <ktraynor at redhat.com>
CC: Aaron Conole <aconole at redhat.com>
Signed-off-by: Robert Wojciechowicz <robertx.wojciechowicz at intel.com>
Co-authored-by: Antonio Fischetti <antonio.fischetti at intel.com>
Signed-off-by: Antonio Fischetti <antonio.fischetti at intel.com>
Acked-by: Ian Stokes <ian.stokes at intel.com>
---
v4:
- code rebased
- manage EEXIST err code after rte_pktmbuf_pool_create
- replaced strncpy with ovs_strzcpy
- added some VLOG_DBG msgs
v3:
- adding memory for corner cases
v2:
- removing mempool reference counter
- making sure mempool name isn't longer than RTE_MEMPOOL_NAMESIZE
---
lib/netdev-dpdk.c | 135 ++++++++++++++++++++++++++++++------------------------
1 file changed, 76 insertions(+), 59 deletions(-)
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 1aaf6f7..35da76a 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -303,14 +303,12 @@ 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;
-static struct ovs_list dpdk_mp_list OVS_GUARDED_BY(dpdk_mp_mutex)
- = OVS_LIST_INITIALIZER(&dpdk_mp_list);
-
struct dpdk_mp {
struct rte_mempool *mp;
int mtu;
int socket_id;
- int refcount;
+ char if_name[IFNAMSIZ];
+ unsigned mp_size;
struct ovs_list list_node OVS_GUARDED_BY(dpdk_mp_mutex);
};
@@ -492,45 +490,81 @@ ovs_rte_pktmbuf_init(struct rte_mempool *mp OVS_UNUSED,
dp_packet_init_dpdk((struct dp_packet *) pkt, pkt->buf_len);
}
+/*
+ * Full DPDK memory pool name must be unique
+ * and cannot be longer than RTE_MEMPOOL_NAMESIZE
+ */
+static char *
+dpdk_mp_name(struct dpdk_mp *dmp)
+{
+ uint32_t h = hash_string(dmp->if_name, 0);
+ char *mp_name = xcalloc(RTE_MEMPOOL_NAMESIZE, sizeof(char));
+ int ret = snprintf(mp_name, RTE_MEMPOOL_NAMESIZE, "ovs_%x_%d_%u",
+ h, dmp->mtu, dmp->mp_size);
+ if (ret < 0 || ret >= RTE_MEMPOOL_NAMESIZE) {
+ return NULL;
+ }
+ return mp_name;
+}
+
static struct dpdk_mp *
-dpdk_mp_create(int socket_id, int mtu)
+dpdk_mp_create(struct netdev_dpdk *dev, int mtu)
{
struct dpdk_mp *dmp;
- unsigned mp_size;
char *mp_name;
+ bool mp_exists = false;
dmp = dpdk_rte_mzalloc(sizeof *dmp);
if (!dmp) {
return NULL;
}
- dmp->socket_id = socket_id;
+ dmp->socket_id = dev->requested_socket_id;
dmp->mtu = mtu;
- dmp->refcount = 1;
- /* 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.
+ ovs_strzcpy(dmp->if_name, dev->up.name, IFNAMSIZ);
+
+ /*
+ * XXX: rough estimation of memory required for 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>
*/
- if (mtu >= ETHER_MTU) {
- mp_size = MAX_NB_MBUF;
- } else {
- mp_size = MIN_NB_MBUF;
- }
+ dmp->mp_size = 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;
do {
- mp_name = xasprintf("ovs_mp_%d_%d_%u", dmp->mtu, dmp->socket_id,
- mp_size);
+ mp_name = dpdk_mp_name(dmp);
+
+ VLOG_DBG("Requesting a mempool of %u mbufs for netdev %s "
+ "with %d Rx and %d Tx queues.",
+ dmp->mp_size, dev->up.name,
+ dev->requested_n_rxq, dev->requested_n_txq);
- dmp->mp = rte_pktmbuf_pool_create(mp_name, mp_size,
+ dmp->mp = rte_pktmbuf_pool_create(mp_name, dmp->mp_size,
MP_CACHE_SZ,
sizeof (struct dp_packet)
- sizeof (struct rte_mbuf),
MBUF_SIZE(mtu)
- sizeof(struct dp_packet),
- socket_id);
+ dmp->socket_id);
if (dmp->mp) {
VLOG_DBG("Allocated \"%s\" mempool with %u mbufs",
- mp_name, mp_size);
+ mp_name, dmp->mp_size);
+ } else if (rte_errno == EEXIST) {
+ /* A mempool with the same name already exists. We just
+ * retrieve its pointer to be returned to the caller. */
+ dmp->mp = rte_mempool_lookup(mp_name);
+ VLOG_DBG("A mempool with name %s already exists at %p.",
+ mp_name, dmp->mp);
+ /* 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. */
+ mp_exists = true;
+ } else {
+ VLOG_DBG("Mempool create failed with error: %s",
+ rte_strerror(rte_errno));
}
free(mp_name);
if (dmp->mp) {
@@ -541,31 +575,20 @@ dpdk_mp_create(int socket_id, int mtu)
rte_mempool_obj_iter(dmp->mp, ovs_rte_pktmbuf_init, NULL);
return dmp;
}
- } while (rte_errno == ENOMEM && (mp_size /= 2) >= MIN_NB_MBUF);
+ } while (!mp_exists &&
+ (rte_errno == ENOMEM && (dmp->mp_size /= 2) >= MIN_NB_MBUF));
rte_free(dmp);
return NULL;
}
static struct dpdk_mp *
-dpdk_mp_get(int socket_id, int mtu)
+dpdk_mp_get(struct netdev_dpdk *dev, int mtu)
{
struct dpdk_mp *dmp;
ovs_mutex_lock(&dpdk_mp_mutex);
- LIST_FOR_EACH (dmp, list_node, &dpdk_mp_list) {
- if (dmp->socket_id == socket_id && dmp->mtu == mtu) {
- dmp->refcount++;
- goto out;
- }
- }
-
- dmp = dpdk_mp_create(socket_id, mtu);
- if (dmp) {
- ovs_list_push_back(&dpdk_mp_list, &dmp->list_node);
- }
-
-out:
+ dmp = dpdk_mp_create(dev, mtu);
ovs_mutex_unlock(&dpdk_mp_mutex);
return dmp;
@@ -574,18 +597,18 @@ out:
static void
dpdk_mp_put(struct dpdk_mp *dmp)
{
+ char *mp_name;
+
if (!dmp) {
return;
}
ovs_mutex_lock(&dpdk_mp_mutex);
- ovs_assert(dmp->refcount);
-
- if (!--dmp->refcount) {
- ovs_list_remove(&dmp->list_node);
- rte_mempool_free(dmp->mp);
- rte_free(dmp);
- }
+ mp_name = dpdk_mp_name(dmp);
+ VLOG_DBG("Releasing \"%s\" mempool", mp_name);
+ free(mp_name);
+ rte_mempool_free(dmp->mp);
+ rte_free(dmp);
ovs_mutex_unlock(&dpdk_mp_mutex);
}
@@ -600,7 +623,7 @@ netdev_dpdk_mempool_configure(struct netdev_dpdk *dev)
uint32_t buf_size = dpdk_buf_size(dev->requested_mtu);
struct dpdk_mp *mp;
- mp = dpdk_mp_get(dev->requested_socket_id, FRAME_LEN_TO_MTU(buf_size));
+ mp = dpdk_mp_get(dev, FRAME_LEN_TO_MTU(buf_size));
if (!mp) {
VLOG_ERR("Failed to create memory pool for netdev "
"%s, with MTU %d on socket %d: %s\n",
@@ -3173,12 +3196,9 @@ netdev_dpdk_reconfigure(struct netdev *netdev)
rte_eth_dev_stop(dev->port_id);
- if (dev->mtu != dev->requested_mtu
- || dev->socket_id != dev->requested_socket_id) {
- err = netdev_dpdk_mempool_configure(dev);
- if (err) {
- goto out;
- }
+ err = netdev_dpdk_mempool_configure(dev);
+ if (err) {
+ goto out;
}
netdev->n_txq = dev->requested_n_txq;
@@ -3216,14 +3236,11 @@ dpdk_vhost_reconfigure_helper(struct netdev_dpdk *dev)
netdev_dpdk_remap_txqs(dev);
- if (dev->requested_socket_id != dev->socket_id
- || dev->requested_mtu != dev->mtu) {
- err = netdev_dpdk_mempool_configure(dev);
- if (err) {
- return err;
- } else {
- netdev_change_seq_changed(&dev->up);
- }
+ err = netdev_dpdk_mempool_configure(dev);
+ if (err) {
+ return err;
+ } else {
+ netdev_change_seq_changed(&dev->up);
}
if (netdev_dpdk_get_vid(dev) >= 0) {
--
2.4.11
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