From 8dbde28d9711475adfe0e9c88505e38743cdc2a7 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <dada1@cosmosbay.com>
Date: Fri, 16 Nov 2007 03:32:10 -0800
Subject: [PATCH] [NET]: NET_CLS_ROUTE : convert ip_rt_acct to per_cpu
variables
ip_rt_acct needs 4096 bytes per cpu to perform some accounting.
It is actually allocated as a single huge array [4096*NR_CPUS]
(rounded up to a power of two)
Converting it to a per cpu variable is wanted to :
- Save space on machines were num_possible_cpus() < NR_CPUS
- Better NUMA placement (each cpu gets memory on its node)
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/ip_input.c | 2 +-
net/ipv4/route.c | 15 +++------------
2 files changed, 4 insertions(+), 13 deletions(-)
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 5b8a7603e606..4068e178d747 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -347,7 +347,7 @@ static int ip_rcv_finish(struct sk_buff *skb)
#ifdef CONFIG_NET_CLS_ROUTE
if (unlikely(skb->dst->tclassid)) {
- struct ip_rt_acct *st = ip_rt_acct + 256*smp_processor_id();
+ struct ip_rt_acct *st = per_cpu_ptr(ip_rt_acct, smp_processor_id());
u32 idx = skb->dst->tclassid;
st[idx&0xFF].o_packets++;
st[idx&0xFF].o_bytes+=skb->len;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 94ef788a2ac6..a21021bf1409 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2858,12 +2858,10 @@ ctl_table ipv4_route_table[] = {
#endif
#ifdef CONFIG_NET_CLS_ROUTE
-struct ip_rt_acct *ip_rt_acct;
-
-/* This code sucks. But you should have seen it before! --RR */
+struct ip_rt_acct *ip_rt_acct __read_mostly;
/* IP route accounting ptr for this logical cpu number. */
-#define IP_RT_ACCT_CPU(i) (ip_rt_acct + i * 256)
+#define IP_RT_ACCT_CPU(cpu) (per_cpu_ptr(ip_rt_acct, cpu))
#ifdef CONFIG_PROC_FS
static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
@@ -2923,16 +2921,9 @@ int __init ip_rt_init(void)
(jiffies ^ (jiffies >> 7)));
#ifdef CONFIG_NET_CLS_ROUTE
- {
- int order;
- for (order = 0;
- (PAGE_SIZE << order) < 256 * sizeof(struct ip_rt_acct) * NR_CPUS; order++)
- /* NOTHING */;
- ip_rt_acct = (struct ip_rt_acct *)__get_free_pages(GFP_KERNEL, order);
+ ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct));
if (!ip_rt_acct)
panic("IP: failed to allocate ip_rt_acct\n");
- memset(ip_rt_acct, 0, PAGE_SIZE << order);
- }
#endif
ipv4_dst_ops.kmem_cachep =