Hi Chris, Chris Mi via dev <[email protected]> writes:
> OVS_DP_F_UNALIGNED is already set, no need to set again. If restarting ovs, > dp is already created. So dpif_netlink_dp_transact() will return EEXIST. > No need to probe again. > > Signed-off-by: Chris Mi <[email protected]> > --- > lib/dpif-netlink.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/lib/dpif-netlink.c b/lib/dpif-netlink.c > index 5f4b60c5a..baa8e4d2a 100644 > --- a/lib/dpif-netlink.c > +++ b/lib/dpif-netlink.c > @@ -411,11 +411,10 @@ dpif_netlink_open(const struct dpif_class *class > OVS_UNUSED, const char *name, > * dispatching, we fall back to the per-vport dispatch mode. > */ > dp_request.user_features &= ~OVS_DP_F_UNSUPPORTED; > - dp_request.user_features |= OVS_DP_F_UNALIGNED; > dp_request.user_features &= ~OVS_DP_F_VPORT_PIDS; > dp_request.user_features |= OVS_DP_F_DISPATCH_UPCALL_PER_CPU; > error = dpif_netlink_dp_transact(&dp_request, &dp, &buf); > - if (error) { > + if (error == EOPNOTSUPP) { > dp_request.user_features &= ~OVS_DP_F_DISPATCH_UPCALL_PER_CPU; > dp_request.user_features |= OVS_DP_F_VPORT_PIDS; > error = dpif_netlink_dp_transact(&dp_request, &dp, &buf); The patch LGTM, there's a remark about this function, though. Before [1] the datapath did not check what user_features were supported, for this reason [2] was needed to avoid the case in which we set OVS_DP_F_DISPATCH_UPCALL_PER_CPU on old kernels without supporting it. I wonder what happens if, in case of kernel without [1] (prior to 5.4), we try to create the datapath during a restart? My impression is that we'll keep transacting receiving EEXIST, and only after opening (without trying to create it) we set the things as we intend. This seems to be confirmed by: ovs-vswitchd 834 [000] 146.180045: probe:ovs_dp_cmd_new__return: (ffffffffc075d290 <- ffffffffacba1a5a) retval=0xffffffef ovs-vswitchd 834 [000] 146.180111: probe:ovs_dp_cmd_new__return: (ffffffffc075d290 <- ffffffffacba1a5a) retval=0xffffffef ovs-vswitchd 834 [000] 146.180212: probe:ovs_dp_cmd_new__return: (ffffffffc075d290 <- ffffffffacba1a5a) retval=0xffffffef Note that I didn't really test it against an old kernel, but I just removed the user_features validation from the kernel code. If confirmed, this is not a problem per se (there should not be a case where this can become a functional problem), it's more about knowing that there's this further chance to clean things up. [1] 95a7233c452a ("net: openvswitch: Set OvS recirc_id from tc chain index") [2] b841e3cd4a28 ("dpif-netlink: Fix feature negotiation for older kernels.") _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
