diff options
Diffstat (limited to 'br-nf-bds/linux2.5/net/ipv4/netfilter/ip_tables.c')
| -rw-r--r-- | br-nf-bds/linux2.5/net/ipv4/netfilter/ip_tables.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/br-nf-bds/linux2.5/net/ipv4/netfilter/ip_tables.c b/br-nf-bds/linux2.5/net/ipv4/netfilter/ip_tables.c index 0b8d07c..f1c7016 100644 --- a/br-nf-bds/linux2.5/net/ipv4/netfilter/ip_tables.c +++ b/br-nf-bds/linux2.5/net/ipv4/netfilter/ip_tables.c @@ -68,13 +68,12 @@ static DECLARE_MUTEX(ipt_mutex); #define inline #endif -/* Locking is simple: we assume at worst case there will be one packet - in user context and one from bottom halves (or soft irq if Alexey's - softnet patch was applied). - +/* We keep a set of rules for each CPU, so we can avoid write-locking - them; doing a readlock_bh() stops packets coming through if we're - in user context. + them in the softirq when updating the counters and therefore + only need to read-lock in the softirq; doing a write_lock_bh() in user + context stops packets coming through and allows user context to read + the counters or update the rules. To be cache friendly on SMP, we arrange them like so: [ n-entries ] |