diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-01-10 20:11:38 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2011-01-10 20:11:38 +0100 |
| commit | 83723d60717f8da0f53f91cf42a845ed56c09662 (patch) | |
| tree | 9d32edc2c6dc4849e63d422f8dad42606b2f984f /net/netfilter/x_tables.c | |
| parent | 45b9f509b7f5d2d792b3c03b78ddc8ec543e921b (diff) | |
| download | linux-83723d60717f8da0f53f91cf42a845ed56c09662.tar.gz | |
netfilter: x_tables: dont block BH while reading counters
Using "iptables -L" with a lot of rules have a too big BH latency.
Jesper mentioned ~6 ms and worried of frame drops.
Switch to a per_cpu seqlock scheme, so that taking a snapshot of
counters doesnt need to block BH (for this cpu, but also other cpus).
This adds two increments on seqlock sequence per ipt_do_table() call,
its a reasonable cost for allowing "iptables -L" not block BH
processing.
Reported-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/x_tables.c')
| -rw-r--r-- | net/netfilter/x_tables.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 80463507420ed..c942376310772 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -1325,7 +1325,8 @@ static int __init xt_init(void) for_each_possible_cpu(i) { struct xt_info_lock *lock = &per_cpu(xt_info_locks, i); - spin_lock_init(&lock->lock); + + seqlock_init(&lock->lock); lock->readers = 0; } |