On Fri, 26 Oct 2018 15:02:19 +1300 Brodie Greenfield <brodie.greenfi...@alliedtelesis.co.nz> wrote:
> We want to be able to keep more spaces available in our queue for > processing incoming multicast traffic (adding (S,G) entries) - this lets > us learn more groups faster, rather than dropping them at this stage. > > Signed-off-by: Brodie Greenfield <brodie.greenfi...@alliedtelesis.co.nz> > --- > Documentation/networking/ip-sysctl.txt | 7 +++++++ > include/net/netns/ipv4.h | 1 + > include/uapi/linux/sysctl.h | 1 + > kernel/sysctl_binary.c | 1 + > net/ipv4/af_inet.c | 2 ++ > net/ipv4/ipmr.c | 4 +++- > net/ipv4/sysctl_net_ipv4.c | 7 +++++++ > 7 files changed, 22 insertions(+), 1 deletion(-) > > diff --git a/Documentation/networking/ip-sysctl.txt > b/Documentation/networking/ip-sysctl.txt > index 960de8fe3f40..dfc70ef6c42b 100644 > --- a/Documentation/networking/ip-sysctl.txt > +++ b/Documentation/networking/ip-sysctl.txt > @@ -864,6 +864,13 @@ ip_local_reserved_ports - list of comma separated ranges > > Default: Empty > > +ip_mr_cache_queue_length - INTEGER > + Limit the number of multicast packets we can have in the queue to be > + resolved. > + Bear in mind that this causes an O(n) traversal of the same size when > + the queue is full. This should be considered if increasing. > + Default: 10 > Thanks for updating documentation. The second two sentences aren't clear. Does it mean that setting queue length causes O(n) traversal or that each multicast packet received causes O(n) traversal > ip_unprivileged_port_start - INTEGER > This is a per-namespace sysctl. It defines the first > unprivileged port in the network namespace. Privileged ports > diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h > index e47503b4e4d1..1ca5cabe2d3b 100644 > --- a/include/net/netns/ipv4.h > +++ b/include/net/netns/ipv4.h > @@ -184,6 +184,7 @@ struct netns_ipv4 { > int sysctl_igmp_max_msf; > int sysctl_igmp_llm_reports; > int sysctl_igmp_qrv; > + int sysctl_ip_mr_cache_queue_length; Maybe unsigned because negative value is not meaningful. > > struct ping_group_range ping_group_range; > > diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h > index d71013fffaf6..32e32d4904cd 100644 > --- a/include/uapi/linux/sysctl.h > +++ b/include/uapi/linux/sysctl.h > @@ -425,6 +425,7 @@ enum > NET_TCP_ALLOWED_CONG_CONTROL=123, > NET_TCP_MAX_SSTHRESH=124, > NET_TCP_FRTO_RESPONSE=125, > + NET_IPV4_IP_MR_CACHE_QUEUE_LENGTH=126, > }; The numeric sysctl enum is considered deprecated, new sysctl's need not be added here. > enum { > diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c > index 07148b497451..8db94e8d97ed 100644 > --- a/kernel/sysctl_binary.c > +++ b/kernel/sysctl_binary.c > @@ -367,6 +367,7 @@ static const struct bin_table bin_net_ipv4_table[] = { > { CTL_INT, NET_IPV4_LOCAL_PORT_RANGE, > "ip_local_port_range" }, > { CTL_INT, NET_IPV4_IGMP_MAX_MEMBERSHIPS, > "igmp_max_memberships" }, > { CTL_INT, NET_IPV4_IGMP_MAX_MSF, "igmp_max_msf" > }, > + { CTL_INT, NET_IPV4_IP_MR_CACHE_QUEUE_LENGTH, > "ip_mr_cache_queue_length" }, > { CTL_INT, NET_IPV4_INET_PEER_THRESHOLD, > "inet_peer_threshold" }, > { CTL_INT, NET_IPV4_INET_PEER_MINTTL, > "inet_peer_minttl" }, > { CTL_INT, NET_IPV4_INET_PEER_MAXTTL, > "inet_peer_maxttl" }, > diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c > index 1fbe2f815474..4b78d12aca36 100644 > --- a/net/ipv4/af_inet.c > +++ b/net/ipv4/af_inet.c > @@ -1818,6 +1818,8 @@ static __net_init int inet_init_net(struct net *net) > net->ipv4.sysctl_igmp_llm_reports = 1; > net->ipv4.sysctl_igmp_qrv = 2; > > + /* ipmr unresolved queue length max */ > + net->ipv4.sysctl_ip_mr_cache_queue_length = 10; Comment here is not necessary, is obvious. > return 0; > } > > diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c > index 5660adcf7a04..2864f80e2f2a 100644 > --- a/net/ipv4/ipmr.c > +++ b/net/ipv4/ipmr.c > @@ -1128,6 +1128,7 @@ static int ipmr_cache_unresolved(struct mr_table *mrt, > vifi_t vifi, > struct mfc_cache *c; > bool found = false; > int err; > + struct net *net = dev_net(dev); The network layer coding style is to use reverse christmas tree style declarations, move this up. > > spin_lock_bh(&mfc_unres_lock); > list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) { > @@ -1140,7 +1141,8 @@ static int ipmr_cache_unresolved(struct mr_table *mrt, > vifi_t vifi, > > if (!found) { > /* Create a new entry if allowable */ > - if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 || > + if (atomic_read(&mrt->cache_resolve_queue_len) >= > + net->ipv4.sysctl_ip_mr_cache_queue_length || > (c = ipmr_cache_alloc_unres()) == NULL) { > spin_unlock_bh(&mfc_unres_lock); > > diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c > index 891ed2f91467..b249932ee24e 100644 > --- a/net/ipv4/sysctl_net_ipv4.c > +++ b/net/ipv4/sysctl_net_ipv4.c > @@ -772,6 +772,13 @@ static struct ctl_table ipv4_net_table[] = { > .mode = 0644, > .proc_handler = proc_dointvec > }, > + { > + .procname = "ip_mr_cache_queue_length", > + .data = > &init_net.ipv4.sysctl_ip_mr_cache_queue_length, > + .maxlen = sizeof(int), > + .mode = 0644, > + .proc_handler = proc_dointvec > + }, > #ifdef CONFIG_IP_MULTICAST > { > .procname = "igmp_qrv", This sysctl is not needed if CONFIG_IP_MULTICAST is not defined.