[ovs-dev] [PATCH 06/13] netdev-dpdk: Do not abort if out of hugepage memory.

[Jarno Rajahalme]

> On Oct 4, 2016, at 6:22 PM, Daniele Di Proietto <diproiettod at vmware.com> wrote:
> 
> We can run out of hugepage memory coming from rte_*alloc() more easily
> than heap coming from malloc().
> 
> Therefore:
> 
> * We should use hugepage memory if we're going to access it only in
>  the slow path.


Should this be “We should NOT use huge page…” instead?

  Jarno

> * We shouldn't abort if we're out of hugepage memory.
> * We should gracefully handle out of memory conditions.
> 
> Signed-off-by: Daniele Di Proietto <diproiettod at vmware.com>
> ---
> lib/netdev-dpdk.c | 62 ++++++++++++++++++++++++++++++++++---------------------
> 1 file changed, 38 insertions(+), 24 deletions(-)
> 
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> index fec3e68..f5523a9 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -436,19 +436,13 @@ dpdk_buf_size(int mtu)
>                      NETDEV_DPDK_MBUF_ALIGN);
> }
> 
> -/* XXX: use dpdk malloc for entire OVS. in fact huge page should be used
> - * for all other segments data, bss and text. */
> -
> +/* Allocates an area of 'sz' bytes from DPDK.  The memory is zero'ed.
> + *
> + * Unlike xmalloc(), this function can return NULL on failure. */
> static void *
> dpdk_rte_mzalloc(size_t sz)
> {
> -    void *ptr;
> -
> -    ptr = rte_zmalloc(OVS_VPORT_DPDK, sz, OVS_CACHE_LINE_SIZE);
> -    if (ptr == NULL) {
> -        out_of_memory();
> -    }
> -    return ptr;
> +    return rte_zmalloc(OVS_VPORT_DPDK, sz, OVS_CACHE_LINE_SIZE);
> }
> 
> /* XXX this function should be called only by pmd threads (or by non pmd
> @@ -483,6 +477,9 @@ dpdk_mp_create(int socket_id, int mtu)
>     unsigned mp_size;
> 
>     dmp = dpdk_rte_mzalloc(sizeof *dmp);
> +    if (!dmp) {
> +        return NULL;
> +    }
>     dmp->socket_id = socket_id;
>     dmp->mtu = mtu;
>     dmp->refcount = 1;
> @@ -801,17 +798,22 @@ netdev_dpdk_alloc(void)
>     return NULL;
> }
> 
> -static void
> -netdev_dpdk_alloc_txq(struct netdev_dpdk *dev, unsigned int n_txqs)
> +static struct dpdk_tx_queue *
> +netdev_dpdk_alloc_txq(unsigned int n_txqs)
> {
> +    struct dpdk_tx_queue *txqs;
>     unsigned i;
> 
> -    dev->tx_q = dpdk_rte_mzalloc(n_txqs * sizeof *dev->tx_q);
> -    for (i = 0; i < n_txqs; i++) {
> -        /* Initialize map for vhost devices. */
> -        dev->tx_q[i].map = OVS_VHOST_QUEUE_MAP_UNKNOWN;
> -        rte_spinlock_init(&dev->tx_q[i].tx_lock);
> +    txqs = dpdk_rte_mzalloc(n_txqs * sizeof *txqs);
> +    if (txqs) {
> +        for (i = 0; i < n_txqs; i++) {
> +            /* Initialize map for vhost devices. */
> +            txqs[i].map = OVS_VHOST_QUEUE_MAP_UNKNOWN;
> +            rte_spinlock_init(&txqs[i].tx_lock);
> +        }
>     }
> +
> +    return txqs;
> }
> 
> static int
> @@ -874,13 +876,18 @@ netdev_dpdk_init(struct netdev *netdev, unsigned int port_no,
>         if (err) {
>             goto unlock;
>         }
> -        netdev_dpdk_alloc_txq(dev, netdev->n_txq);
> +        dev->tx_q = netdev_dpdk_alloc_txq(netdev->n_txq);
>     } else {
> -        netdev_dpdk_alloc_txq(dev, OVS_VHOST_MAX_QUEUE_NUM);
> +        dev->tx_q = netdev_dpdk_alloc_txq(OVS_VHOST_MAX_QUEUE_NUM);
>         /* Enable DPDK_DEV_VHOST device and set promiscuous mode flag. */
>         dev->flags = NETDEV_UP | NETDEV_PROMISC;
>     }
> 
> +    if (!dev->tx_q) {
> +        err = ENOMEM;
> +        goto unlock;
> +    }
> +
>     ovs_list_push_back(&dpdk_list, &dev->list_node);
> 
> unlock:
> @@ -1226,7 +1233,11 @@ netdev_dpdk_rxq_alloc(void)
> {
>     struct netdev_rxq_dpdk *rx = dpdk_rte_mzalloc(sizeof *rx);
> 
> -    return &rx->up;
> +    if (rx) {
> +        return &rx->up;
> +    }
> +
> +    return NULL;
> }
> 
> static struct netdev_rxq_dpdk *
> @@ -2352,7 +2363,7 @@ netdev_dpdk_remap_txqs(struct netdev_dpdk *dev)
>     int *enabled_queues, n_enabled = 0;
>     int i, k, total_txqs = dev->up.n_txq;
> 
> -    enabled_queues = dpdk_rte_mzalloc(total_txqs * sizeof *enabled_queues);
> +    enabled_queues = xcalloc(total_txqs, sizeof *enabled_queues);
> 
>     for (i = 0; i < total_txqs; i++) {
>         /* Enabled queues always mapped to themselves. */
> @@ -2379,7 +2390,7 @@ netdev_dpdk_remap_txqs(struct netdev_dpdk *dev)
>         VLOG_DBG("%2d --> %2d", i, dev->tx_q[i].map);
>     }
> 
> -    rte_free(enabled_queues);
> +    free(enabled_queues);
> }
> 
> /*
> @@ -2620,7 +2631,7 @@ dpdk_ring_create(const char dev_name[], unsigned int port_no,
>     int err;
> 
>     ivshmem = dpdk_rte_mzalloc(sizeof *ivshmem);
> -    if (ivshmem == NULL) {
> +    if (!ivshmem) {
>         return ENOMEM;
>     }
> 
> @@ -2977,7 +2988,10 @@ netdev_dpdk_reconfigure(struct netdev *netdev)
> 
>     rte_free(dev->tx_q);
>     err = dpdk_eth_dev_init(dev);
> -    netdev_dpdk_alloc_txq(dev, netdev->n_txq);
> +    dev->tx_q = netdev_dpdk_alloc_txq(netdev->n_txq);
> +    if (!dev->tx_q) {
> +        err = ENOMEM;
> +    }
> 
>     netdev_change_seq_changed(netdev);
> 
> -- 
> 2.9.3
> 
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