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authorEric Dumazet <eric.dumazet@gmail.com>2010-08-02 16:49:01 +0200
committerPatrick McHardy <kaber@trash.net>2010-08-02 16:49:01 +0200
commit24b36f0193467fa727b85b4c004016a8dae999b9 (patch)
treed9518ed0ef2012fd14567d03b500295dfb7fe7e0 /net/ipv4/netfilter/ip_tables.c
parent7df0884ce144396fc151f2af7a73d5fb305f9b03 (diff)
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netfilter: {ip,ip6,arp}_tables: dont block bottom half more than necessary
We currently disable BH for the whole duration of get_counters() On machines with a lot of cpus and large tables, this might be too long. We can disable preemption during the whole function, and disable BH only while fetching counters for the current cpu. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/ipv4/netfilter/ip_tables.c')
-rw-r--r--net/ipv4/netfilter/ip_tables.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 3c584a6765b..c439721b165 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -884,7 +884,7 @@ get_counters(const struct xt_table_info *t,
struct ipt_entry *iter;
unsigned int cpu;
unsigned int i;
- unsigned int curcpu;
+ unsigned int curcpu = get_cpu();
/* Instead of clearing (by a previous call to memset())
* the counters and using adds, we set the counters
@@ -894,14 +894,16 @@ get_counters(const struct xt_table_info *t,
* if new softirq were to run and call ipt_do_table
*/
local_bh_disable();
- curcpu = smp_processor_id();
-
i = 0;
xt_entry_foreach(iter, t->entries[curcpu], t->size) {
SET_COUNTER(counters[i], iter->counters.bcnt,
iter->counters.pcnt);
++i;
}
+ local_bh_enable();
+ /* Processing counters from other cpus, we can let bottom half enabled,
+ * (preemption is disabled)
+ */
for_each_possible_cpu(cpu) {
if (cpu == curcpu)
@@ -915,7 +917,7 @@ get_counters(const struct xt_table_info *t,
}
xt_info_wrunlock(cpu);
}
- local_bh_enable();
+ put_cpu();
}
static struct xt_counters *alloc_counters(const struct xt_table *table)