Thanks Jarno for your feedback, will respin a new version with the suggested fix.
Regards, Antonio > -----Original Message----- > From: Jarno Rajahalme [mailto:[email protected]] > Sent: Thursday, January 5, 2017 11:30 PM > To: Fischetti, Antonio <[email protected]> > Cc: [email protected]; Bodireddy, Bhanuprakash > <[email protected]> > Subject: Re: [PATCH v2] dpcls: Avoid one 8-byte chunk in subtable mask. > > > > On Jan 5, 2017, at 1:03 AM, [email protected] wrote: > > > > This patch allows to skip the chunk comprising of dp_hash and in_port > > in the subtable mask when the packet is not recirculated. This will > > slightly speed up the hash computation as one expensive function call > > to hash_add64() can be skipped. > > For each new netdev flow we wildcard in_port in the mask, so in the > > physical case where dp_hash is also wildcarded, the resulting 8-byte > > chunk will not be part of the subtable mask. > > > > It appears you have not run the testsuite with this patch, as it > consistently fails. This is due to dumped flows now missing the in_port > match, which is caused by the subtable mask change. This can be fixed like > this: > > diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c > index 0b73056..5f6fc01 100644 > --- a/lib/dpif-netdev.c > +++ b/lib/dpif-netdev.c > @@ -2098,6 +2098,9 @@ dp_netdev_flow_to_dpif_flow(const struct > dp_netdev_flow *netdev_flow, > }; > > miniflow_expand(&netdev_flow->cr.mask->mf, &wc.masks); > + /* in_port is exact matched, but we have left it out from the > mask for > + * optimization reasons. Add in_port back to the mask. */ > + wc.masks.in_port.odp_port = ODPP_NONE; > > /* Key */ > offset = key_buf->size; > > > The idea behind is that all the packets within a given dpcls will > > have the same in_port value and typically dp_hash == 0. So they will > > have the same 8-bytes chunk in their {dp_hash, in_port} portion of the > > miniflow. This doesn't contribute effectively in spreading hash values > > and avoiding collisions. > > > > v2: Using ovs_assert > > > > Now there are two asserts for the same thing, I think the latter (the old > one) should be removed. > > Jarno > > > Signed-off-by: Antonio Fischetti <[email protected]> > > Signed-off-by: Bhanuprakash Bodireddy <[email protected]> > > Co-authored-by: Bhanuprakash Bodireddy > <[email protected]> > > Signed-off-by: Jarno Rajahalme <[email protected]> > > Co-authored-by: Jarno Rajahalme <[email protected]> > > --- > > lib/dpif-netdev.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c > > index 1a47a45..68b434f 100644 > > --- a/lib/dpif-netdev.c > > +++ b/lib/dpif-netdev.c > > @@ -2278,7 +2278,18 @@ dp_netdev_flow_add(struct dp_netdev_pmd_thread > *pmd, > > struct dpcls *cls; > > odp_port_t in_port = match->flow.in_port.odp_port; > > > > + /* As we select the dpcls based on the port number, each netdev > flow > > + * belonging to the same dpcls will have the same odp_port value. > > + * For performance reasons here we wildcard odp_port in the mask. > In the > > + * physical case where dp_hash is also wildcarded, the resulting 8- > byte > > + * chunk {dp_hash, in_port} will be ignored by > netdev_flow_mask_init() and > > + * will not be part of the subtable mask. > > + * This will speed up the hash computation during dpcls_lookup() > because > > + * one call to hash_add64() will be skipped. */ > > + ovs_assert(match->wc.masks.in_port.odp_port == ODPP_NONE); > > + match->wc.masks.in_port.odp_port = 0; > > netdev_flow_mask_init(&mask, match); > > + match->wc.masks.in_port.odp_port = ODPP_NONE; > > /* Make sure wc does not have metadata. */ > > ovs_assert(!FLOWMAP_HAS_FIELD(&mask.mf.map, metadata) > > && !FLOWMAP_HAS_FIELD(&mask.mf.map, regs)); > > -- > > 2.4.11 > > _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
