Sounds good. I'll incorporate those changes. > -----Original Message----- > From: Darrell Ball [mailto:[email protected]] > Sent: Monday, June 26, 2017 4:53 PM > To: O Mahony, Billy <[email protected]>; [email protected] > Subject: Re: [ovs-dev] [PATCH v6] dpif-netdev: Assign ports to pmds on non- > local numa node. > > > > On 6/26/17, 6:52 AM, "O Mahony, Billy" <[email protected]> wrote: > > Hi Darrell, > > > > Thanks for reviewing. > > > > > -----Original Message----- > > > From: Darrell Ball [mailto:[email protected]] > > > Sent: Monday, June 26, 2017 8:04 AM > > > To: O Mahony, Billy <[email protected]>; [email protected] > > > Subject: Re: [ovs-dev] [PATCH v6] dpif-netdev: Assign ports to pmds on > non- > > > local numa node. > > > > > > I think this is helpful in some cases where lower performance is an > > > acceptable tradeoff with more frugal and/or more flexible usage of cpu > > > resources. > > > > > > I did not test it since Ian has already done that, but I reviewed the > code > > > change and other related code. > > > > > > One comment inline regarding the added documentation. > > > > > > Otherwise, Acked-by: Darrell Ball <[email protected]> > > > > > > > > > > > > On 5/10/17, 8:59 AM, "[email protected] on behalf of > Billy > > > O'Mahony" <[email protected] on behalf of > > > [email protected]> wrote: > > > > > > From: billyom <[email protected]> > > > > > > Previously if there is no available (non-isolated) pmd on the numa > node > > > for a port then the port is not polled at all. This can result in a > > > non-operational system until such time as nics are physically > > > repositioned. It is preferable to operate with a pmd on the 'wrong' > numa > > > node albeit with lower performance. Local pmds are still chosen when > > > available. > > > > > > Signed-off-by: Billy O'Mahony <[email protected]> > > > --- > > > v6: Change 'port' to 'queue' in a warning msg > > > v5: Fix warning msg; Update same in docs > > > v4: Fix a checkpatch error > > > v3: Fix warning messages not appearing when using multiqueue > > > v2: Add details of warning messages into docs > > > > > > Documentation/intro/install/dpdk.rst | 10 +++++++++ > > > lib/dpif-netdev.c | 43 > +++++++++++++++++++++++++++++++--- > > > -- > > > 2 files changed, 48 insertions(+), 5 deletions(-) > > > > > > diff --git a/Documentation/intro/install/dpdk.rst > > > b/Documentation/intro/install/dpdk.rst > > > index d1c0e65..7a66bff 100644 > > > --- a/Documentation/intro/install/dpdk.rst > > > +++ b/Documentation/intro/install/dpdk.rst > > > @@ -460,6 +460,16 @@ affinitized accordingly. > > > pmd thread on a NUMA node is only created if there is at least > one > DPDK > > > interface from that NUMA node added to OVS. > > > > > > + .. note:: > > > + On NUMA systems PCI devices are also local to a NUMA node. Rx > > > queues for > > > + PCI device will assigned to a pmd on it's local NUMA node if > pmd- > cpu- > > > mask > > > + has created a pmd thread on that NUMA node. If not the queue > will > be > > > + assigned to a pmd on a remote NUMA node. > > > > > > > > > > > > I think the below text is a bit more accurate > > > + .. note:: > > > + On NUMA systems PCI devices are also local to a NUMA node. Rx > queues > > > for > > > + a PCI device will be assigned to a pmd on it's local NUMA node. > > > > [[BO'M]] > > Re suggested sentence: "Rx queues for a PCI device will be assigned to a > pmd on it's local NUMA node." > > However, with this patch that is no longer always the case. Assignment to > a > pmd on it's local NUMA node will be preferred but it that is not possible then > assignment will be done to a PMD on a non-local NUMA node. > > > > Is the suggested change in order to emphasize that a PMD is created if > specified in pmd-cpu-mask but not actually scheduled by the OS unless at > least one rxq is assigned to it? That case is covered in the preceeding > paragraph (which is not modified by this patch) "A pmd thread on a NUMA > node is only created if there is at least one DPDK interface from that NUMA > node added to OVS." Which, now I read it should be modified to read "A > PMD thread only becomes runnable if there is at least one DPDK interface > assigned to it." > > > [Darrell] > I unintentionally deleted the below line of text from the beginning of the > following paragraph – “my bad”. > “If not the queue will be assigned to a pmd on a remote NUMA node. “ > > > > The full text was intended to be > > + .. note:: > + On NUMA systems PCI devices are also local to a NUMA node. Rx queues > for > + a PCI device will be assigned to a pmd on it's local NUMA node. A pmd is > + created if at least one dpdk interface is added to OVS on that NUMA node > or > + if the pmd-cpu-mask has created a pmd thread on that NUMA node. If > not the queue will be > + assigned to a pmd on a remote NUMA node. This will result in reduced > + maximum throughput on that device. In the case such a queue > assignment > + is made a warning message will be logged: "There's no available (non- > + isolated) pmd thread on numa node N. Queue Q on port P will be assigned > to > + the pmd on core C (numa node N'). Expect reduced performance." > + > > which is not totally accurate. > > Also, as you pointed out, I also added a redundant line from the above > paragraph I expected one .. note:: > and you added a second. > > This is getting confusing. > How about dividing the thread and queue discussions more cleanly and > adding more context. > > .. note:: > A pmd thread on a NUMA node is only created if there is at least one DPDK > interface from that NUMA node added to OVS. A pmd thread is created by > default on a core of a NUMA node or when a specified pmd-cpu-mask has > indicated so. > > .. note:: > On NUMA systems PCI devices are also local to a NUMA node. Unbound Rx > queues for a PCI device will assigned to a pmd on it's local NUMA node if a > non-isolated PMD exists on that NUMA node. If not, the queue will be > assigned to a non-isolated pmd on a remote NUMA node. This will result in > reduced maximum throughput on that device. In the case such, a queue > assignment is made a warning message will be logged: "There's no available > (non-isolated) pmd thread on numa node N. Queue Q on port P will > be assigned to the pmd on core C (numa node N'). Expect reduced > performance." > > > > A pmd is > > > + created if at least one dpdk interface is added to OVS on that NUMA > node > > > or > > > + if the pmd-cpu-mask has created a pmd thread on that NUMA node. > > > > [[BO'M]] > > Is this part of the suggested change in order to emphasize that a PMD is > created if specified in pmd-cpu-mask but not actually scheduled by the OS > unless at least one rxq is assigned to it? (introduced 2788a1b). That detail > is > covered somewhat in the preceding paragraph (which is not modified by this > patch) "A pmd thread on a NUMA node is only created if there is at least one > DPDK interface from that NUMA node added to OVS." > > > > Which, now I read it should be modified to actually reflect that. What do > you think? > > > [Darrell] see above comment > > > > > > > > > + This will result in reduced > > > + maximum throughput on that device. In the case such a queue > > > assignment > > > + is made a warning message will be logged: "There's no available > (non- > > > + isolated) pmd thread on numa node N. Queue Q on port P will be > > > assigned to > > > + the pmd on core C (numa node N'). Expect reduced performance." > > > + > > > - QEMU vCPU thread Affinity > > > > > > A VM performing simple packet forwarding or running complex > packet > > > pipelines > > > diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c > > > index b3a0806..34f1963 100644 > > > --- a/lib/dpif-netdev.c > > > +++ b/lib/dpif-netdev.c > > > @@ -3149,10 +3149,13 @@ rr_numa_list_lookup(struct rr_numa_list > *rr, > > > int numa_id) > > > } > > > > > > static void > > > -rr_numa_list_populate(struct dp_netdev *dp, struct rr_numa_list > *rr) > > > +rr_numa_list_populate(struct dp_netdev *dp, struct rr_numa_list > *rr, > > > + int *all_numa_ids, unsigned all_numa_ids_sz, > > > + int *num_ids_written) > > > { > > > struct dp_netdev_pmd_thread *pmd; > > > struct rr_numa *numa; > > > + unsigned idx = 0; > > > > > > hmap_init(&rr->numas); > > > > > > @@ -3170,7 +3173,11 @@ rr_numa_list_populate(struct dp_netdev > *dp, > > > struct rr_numa_list *rr) > > > numa->n_pmds++; > > > numa->pmds = xrealloc(numa->pmds, numa->n_pmds * sizeof > > > *numa->pmds); > > > numa->pmds[numa->n_pmds - 1] = pmd; > > > + > > > + all_numa_ids[idx % all_numa_ids_sz] = pmd->numa_id; > > > + idx++; > > > } > > > + *num_ids_written = idx; > > > } > > > > > > static struct dp_netdev_pmd_thread * > > > @@ -3202,8 +3209,15 @@ rxq_scheduling(struct dp_netdev *dp, bool > > > pinned) OVS_REQUIRES(dp->port_mutex) > > > { > > > struct dp_netdev_port *port; > > > struct rr_numa_list rr; > > > + int all_numa_ids [64]; > > > + int all_numa_ids_sz = sizeof all_numa_ids / sizeof > all_numa_ids[0]; > > > + unsigned all_numa_ids_idx = 0; > > > + int all_numa_ids_max_idx = 0; > > > + int num_numa_ids = 0; > > > > > > - rr_numa_list_populate(dp, &rr); > > > + rr_numa_list_populate(dp, &rr, all_numa_ids, all_numa_ids_sz, > > > + &num_numa_ids); > > > + all_numa_ids_max_idx = MIN(num_numa_ids - 1, all_numa_ids_sz > - 1); > > > > > > HMAP_FOR_EACH (port, node, &dp->ports) { > > > struct rr_numa *numa; > > > @@ -3234,10 +3248,29 @@ rxq_scheduling(struct dp_netdev *dp, bool > > > pinned) OVS_REQUIRES(dp->port_mutex) > > > } > > > } else if (!pinned && q->core_id == OVS_CORE_UNSPEC) { > > > if (!numa) { > > > - VLOG_WARN("There's no available (non isolated) > pmd > thread " > > > + if (all_numa_ids_max_idx < 0) { > > > + VLOG_ERR("There is no available > (non-isolated) pmd " > > > + "thread for port \'%s\' queue %d. > This queue " > > > + "will not be polled. Is > pmd-cpu-mask set to " > > > + "zero? Or are all PMDs isolated > to other " > > > + "queues?", > netdev_get_name(port->netdev), > > > + qid); > > > + continue; > > > + } > > > + int alt_numa_id = > all_numa_ids[all_numa_ids_idx]; > > > + struct rr_numa *alt_numa; > > > + alt_numa = rr_numa_list_lookup(&rr, > alt_numa_id); > > > + q->pmd = rr_numa_get_pmd(alt_numa); > > > + VLOG_WARN("There's no available (non-isolated) > pmd > thread " > > > "on numa node %d. Queue %d on port > \'%s\' will " > > > - "not be polled.", > > > - numa_id, qid, > netdev_get_name(port->netdev)); > > > + "be assigned to the pmd on core %d " > > > + "(numa node %d). Expect reduced > performance.", > > > + numa_id, qid, > netdev_get_name(port->netdev), > > > + q->pmd->core_id, q->pmd->numa_id); > > > + all_numa_ids_idx++; > > > + if (all_numa_ids_idx > all_numa_ids_max_idx) { > > > + all_numa_ids_idx = 0; > > > + } > > > } else { > > > q->pmd = rr_numa_get_pmd(numa); > > > } > > > -- > > > 2.7.4 > > > > > > _______________________________________________ > > > dev mailing list > > > [email protected] > > > https://urldefense.proofpoint.com/v2/url?u=https- > 3A__mail.openvswitch.org_mailman_listinfo_ovs- > 2Ddev&d=DwIGaQ&c=uilaK90D4TOVoH58JNXRgQ&r=BVhFA09CGX7JQ5Ih- > uZnsw&m=gjJwFxs- > cPdXvKIlpDPy6Wk6vbKVeJuDjxVKrmLbI_E&s=iK8lUsArOqfRzfqIj6IYOGIAO03 > YY-a3eKUDZWt18Ig&e= > > > > > > >
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