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authorEric Dumazet <eric.dumazet@gmail.com>2010-05-31 16:41:35 +0200
committerPatrick McHardy <kaber@trash.net>2010-05-31 16:41:35 +0200
commit7489aec8eed4f2f1eb3b4d35763bd3ea30b32ef5 (patch)
treefe2450679dc217183421e606b3912641545596bd /net
parentc936e8bd1de2fa50c49e3df6fa5036bf07870b67 (diff)
downloadlinux-7489aec8eed4f2f1eb3b4d35763bd3ea30b32ef5.tar.gz
netfilter: xtables: stackptr should be percpu
commit f3c5c1bfd4 (netfilter: xtables: make ip_tables reentrant)
introduced a performance regression, because stackptr array is shared by
all cpus, adding cache line ping pongs. (16 cpus share a 64 bytes cache
line)

Fix this using alloc_percpu()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-By: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/netfilter/ip_tables.c2
-rw-r--r--net/ipv6/netfilter/ip6_tables.c2
-rw-r--r--net/netfilter/x_tables.c13
3 files changed, 5 insertions, 12 deletions
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 63958f3394a5..4b6c5ca610fc 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -336,7 +336,7 @@ ipt_do_table(struct sk_buff *skb,
 	cpu        = smp_processor_id();
 	table_base = private->entries[cpu];
 	jumpstack  = (struct ipt_entry **)private->jumpstack[cpu];
-	stackptr   = &private->stackptr[cpu];
+	stackptr   = per_cpu_ptr(private->stackptr, cpu);
 	origptr    = *stackptr;
 
 	e = get_entry(table_base, private->hook_entry[hook]);
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 6f517bd83692..9d2d68f0e605 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -363,7 +363,7 @@ ip6t_do_table(struct sk_buff *skb,
 	cpu        = smp_processor_id();
 	table_base = private->entries[cpu];
 	jumpstack  = (struct ip6t_entry **)private->jumpstack[cpu];
-	stackptr   = &private->stackptr[cpu];
+	stackptr   = per_cpu_ptr(private->stackptr, cpu);
 	origptr    = *stackptr;
 
 	e = get_entry(table_base, private->hook_entry[hook]);
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 47b1e7917a9c..e34622fa0003 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -699,10 +699,8 @@ void xt_free_table_info(struct xt_table_info *info)
 		vfree(info->jumpstack);
 	else
 		kfree(info->jumpstack);
-	if (sizeof(unsigned int) * nr_cpu_ids > PAGE_SIZE)
-		vfree(info->stackptr);
-	else
-		kfree(info->stackptr);
+
+	free_percpu(info->stackptr);
 
 	kfree(info);
 }
@@ -753,14 +751,9 @@ static int xt_jumpstack_alloc(struct xt_table_info *i)
 	unsigned int size;
 	int cpu;
 
-	size = sizeof(unsigned int) * nr_cpu_ids;
-	if (size > PAGE_SIZE)
-		i->stackptr = vmalloc(size);
-	else
-		i->stackptr = kmalloc(size, GFP_KERNEL);
+	i->stackptr = alloc_percpu(unsigned int);
 	if (i->stackptr == NULL)
 		return -ENOMEM;
-	memset(i->stackptr, 0, size);
 
 	size = sizeof(void **) * nr_cpu_ids;
 	if (size > PAGE_SIZE)