| Message ID | 1531220774-219768-6-git-send-email-tiago.lam@intel.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Ian Stokes |
| Headers | show |
| Series | Support multi-segment mbufs | expand |
On 7/10/2018 12:06 PM, Tiago Lam wrote: > A new mutex, 'nonpmd_mp_mutex', has been introduced to serialise > allocation and free operations by non-pmd threads on a given mempool. > > free_dpdk_buf() has been modified to make use of the introduced mutex. > 1 comment Below Tiago. > Signed-off-by: Tiago Lam <tiago.lam@intel.com> > Acked-by: Eelco Chaudron <echaudro@redhat.com> > --- > lib/netdev-dpdk.c | 30 +++++++++++++++++++++++++++--- > 1 file changed, 27 insertions(+), 3 deletions(-) > > diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c > index a68f78a..72b9955 100644 > --- a/lib/netdev-dpdk.c > +++ b/lib/netdev-dpdk.c > @@ -322,6 +322,16 @@ static struct ovs_mutex dpdk_mp_mutex OVS_ACQ_AFTER(dpdk_mutex) > static struct ovs_list dpdk_mp_list OVS_GUARDED_BY(dpdk_mp_mutex) > = OVS_LIST_INITIALIZER(&dpdk_mp_list); > > +/* This mutex must be used by non pmd threads when allocating or freeing > + * mbufs through mempools, when outside of the `non_pmd_mutex` mutex, in struct > + * dp_netdev. > + * The reason, as pointed out in the "Known Issues" section in DPDK's EAL docs, > + * is that the implementation on which mempool is based off is non-preemptable. > + * Since non-pmds may end up not being pinned this could lead to the preemption > + * between non-pmds performing operations on the same mempool, which could lead > + * to memory corruption. */ > +static struct ovs_mutex nonpmd_mp_mutex = OVS_MUTEX_INITIALIZER; > + > struct dpdk_mp { > struct rte_mempool *mp; > int mtu; > @@ -492,6 +502,8 @@ struct netdev_rxq_dpdk { > dpdk_port_t port_id; > }; > > +static bool dpdk_thread_is_pmd(void); > + > static void netdev_dpdk_destruct(struct netdev *netdev); > static void netdev_dpdk_vhost_destruct(struct netdev *netdev); > > @@ -525,6 +537,12 @@ dpdk_buf_size(int mtu) > NETDEV_DPDK_MBUF_ALIGN); > } > > +static bool > +dpdk_thread_is_pmd(void) > +{ > + return rte_lcore_id() != NON_PMD_CORE_ID; > +} > + > /* Allocates an area of 'sz' bytes from DPDK. The memory is zero'ed. > * > * Unlike xmalloc(), this function can return NULL on failure. */ > @@ -535,11 +553,17 @@ dpdk_rte_mzalloc(size_t sz) > } > > void > -free_dpdk_buf(struct dp_packet *p) > +free_dpdk_buf(struct dp_packet *packet) > { > - struct rte_mbuf *pkt = (struct rte_mbuf *) p; > + if (!dpdk_thread_is_pmd()) { > + ovs_mutex_lock(&nonpmd_mp_mutex); > + } > > - rte_pktmbuf_free(pkt); > + rte_pktmbuf_free(&packet->mbuf); > + > + if (!dpdk_thread_is_pmd()) { > + ovs_mutex_unlock(&nonpmd_mp_mutex); > + } This causes build failures for travis as nonpmd_mp_mutex will not be held on every path through the code. https://travis-ci.org/istokes/ovs/jobs/402193295 Ian > } > > static void >
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index a68f78a..72b9955 100644 --- a/lib/netdev-dpdk.c +++ b/lib/netdev-dpdk.c @@ -322,6 +322,16 @@ static struct ovs_mutex dpdk_mp_mutex OVS_ACQ_AFTER(dpdk_mutex) static struct ovs_list dpdk_mp_list OVS_GUARDED_BY(dpdk_mp_mutex) = OVS_LIST_INITIALIZER(&dpdk_mp_list); +/* This mutex must be used by non pmd threads when allocating or freeing + * mbufs through mempools, when outside of the `non_pmd_mutex` mutex, in struct + * dp_netdev. + * The reason, as pointed out in the "Known Issues" section in DPDK's EAL docs, + * is that the implementation on which mempool is based off is non-preemptable. + * Since non-pmds may end up not being pinned this could lead to the preemption + * between non-pmds performing operations on the same mempool, which could lead + * to memory corruption. */ +static struct ovs_mutex nonpmd_mp_mutex = OVS_MUTEX_INITIALIZER; + struct dpdk_mp { struct rte_mempool *mp; int mtu; @@ -492,6 +502,8 @@ struct netdev_rxq_dpdk { dpdk_port_t port_id; }; +static bool dpdk_thread_is_pmd(void); + static void netdev_dpdk_destruct(struct netdev *netdev); static void netdev_dpdk_vhost_destruct(struct netdev *netdev); @@ -525,6 +537,12 @@ dpdk_buf_size(int mtu) NETDEV_DPDK_MBUF_ALIGN); } +static bool +dpdk_thread_is_pmd(void) +{ + return rte_lcore_id() != NON_PMD_CORE_ID; +} + /* Allocates an area of 'sz' bytes from DPDK. The memory is zero'ed. * * Unlike xmalloc(), this function can return NULL on failure. */ @@ -535,11 +553,17 @@ dpdk_rte_mzalloc(size_t sz) } void -free_dpdk_buf(struct dp_packet *p) +free_dpdk_buf(struct dp_packet *packet) { - struct rte_mbuf *pkt = (struct rte_mbuf *) p; + if (!dpdk_thread_is_pmd()) { + ovs_mutex_lock(&nonpmd_mp_mutex); + } - rte_pktmbuf_free(pkt); + rte_pktmbuf_free(&packet->mbuf); + + if (!dpdk_thread_is_pmd()) { + ovs_mutex_unlock(&nonpmd_mp_mutex); + } } static void