From b195167fcf089dbdc650bb874084555035f07f98 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sat, 27 Feb 2010 19:41:51 +0000 Subject: [PATCH] bridge: Add hash elasticity/max sysfs entries This patch allows the user to control the hash elasticity/max parameters. The elasticity setting does not take effect until the next new multicast group is added. At which point it is checked and if after rehashing it still can't be satisfied then snooping will be disabled. The max setting on the other hand takes effect immediately. It must be a power of two and cannot be set to a value less than the current number of multicast group entries. This is the only way to shrink the multicast hash. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 41 +++++++++++++++++++++++++++++++++++++++ net/bridge/br_private.h | 1 + net/bridge/br_sysfs_br.c | 39 +++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index c7a1095ed84a..2559fb539836 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -1261,3 +1262,43 @@ unlock: return err; } + +int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val) +{ + int err = -ENOENT; + u32 old; + + spin_lock(&br->multicast_lock); + if (!netif_running(br->dev)) + goto unlock; + + err = -EINVAL; + if (!is_power_of_2(val)) + goto unlock; + if (br->mdb && val < br->mdb->size) + goto unlock; + + err = 0; + + old = br->hash_max; + br->hash_max = val; + + if (br->mdb) { + if (br->mdb->old) { + err = -EEXIST; +rollback: + br->hash_max = old; + goto unlock; + } + + err = br_mdb_rehash(&br->mdb, br->hash_max, + br->hash_elasticity); + if (err) + goto rollback; + } + +unlock: + spin_unlock(&br->multicast_lock); + + return err; +} diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index bf162fa6b23b..9191198c4f1b 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -301,6 +301,7 @@ extern int br_multicast_set_router(struct net_bridge *br, unsigned long val); extern int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val); extern int br_multicast_toggle(struct net_bridge *br, unsigned long val); +extern int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val); #else static inline int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port, diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c index 0ab288332fc5..d2ee53b3ad7d 100644 --- a/net/bridge/br_sysfs_br.c +++ b/net/bridge/br_sysfs_br.c @@ -378,6 +378,43 @@ static ssize_t store_multicast_snooping(struct device *d, } static DEVICE_ATTR(multicast_snooping, S_IRUGO | S_IWUSR, show_multicast_snooping, store_multicast_snooping); + +static ssize_t show_hash_elasticity(struct device *d, + struct device_attribute *attr, char *buf) +{ + struct net_bridge *br = to_bridge(d); + return sprintf(buf, "%u\n", br->hash_elasticity); +} + +static int set_elasticity(struct net_bridge *br, unsigned long val) +{ + br->hash_elasticity = val; + return 0; +} + +static ssize_t store_hash_elasticity(struct device *d, + struct device_attribute *attr, + const char *buf, size_t len) +{ + return store_bridge_parm(d, buf, len, set_elasticity); +} +static DEVICE_ATTR(hash_elasticity, S_IRUGO | S_IWUSR, show_hash_elasticity, + store_hash_elasticity); + +static ssize_t show_hash_max(struct device *d, struct device_attribute *attr, + char *buf) +{ + struct net_bridge *br = to_bridge(d); + return sprintf(buf, "%u\n", br->hash_max); +} + +static ssize_t store_hash_max(struct device *d, struct device_attribute *attr, + const char *buf, size_t len) +{ + return store_bridge_parm(d, buf, len, br_multicast_set_hash_max); +} +static DEVICE_ATTR(hash_max, S_IRUGO | S_IWUSR, show_hash_max, + store_hash_max); #endif static struct attribute *bridge_attrs[] = { @@ -402,6 +439,8 @@ static struct attribute *bridge_attrs[] = { #ifdef CONFIG_BRIDGE_IGMP_SNOOPING &dev_attr_multicast_router.attr, &dev_attr_multicast_snooping.attr, + &dev_attr_hash_elasticity.attr, + &dev_attr_hash_max.attr, #endif NULL }; -- 2.34.1