On 03/07/2018 10:49, Eelco Chaudron wrote: > > > On 28 Jun 2018, at 17:41, 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. >> >> Signed-off-by: Tiago Lam <tiago....@intel.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 c5c6aab..5c62d85 100644 >> --- a/lib/netdev-dpdk.c >> +++ b/lib/netdev-dpdk.c >> @@ -294,6 +294,16 @@ static struct ovs_mutex dpdk_mp_mutex >> OVS_ACQ_AFTER(dpdk_mutex) >> static struct ovs_list dpdk_mp_free_list >> OVS_GUARDED_BY(dpdk_mp_mutex) >> = OVS_LIST_INITIALIZER(&dpdk_mp_free_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; >> + >> /* Wrapper for a mempool released but not yet freed. */ >> struct dpdk_mp { >> struct rte_mempool *mp; >> @@ -462,6 +472,8 @@ 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); >> >> @@ -495,6 +507,12 @@ 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. */ >> @@ -505,11 +523,17 @@ 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((struct rte_mbuf *) packet); > > Rather than casting it, it should be &packet->mbuf, some one might > change the order in the dp_packet structure. >
Missed this one. I'll do this for v2, thanks. Tiago. _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev