summaryrefslogtreecommitdiffstats
path: root/net
diff options
context:
space:
mode:
authorEric Dumazet <eric.dumazet@gmail.com>2011-11-08 13:04:43 +0000
committerDavid S. Miller <davem@davemloft.net>2011-11-09 16:04:20 -0500
commitacb32ba3dee66d58704caeeb8c6ff95f60efdc66 (patch)
treeb5c1d6d5575a7b75c7c816e0809690f58401715c /net
parente56c57d0d3fdbbdf583d3af96bfb803b8dfa713e (diff)
downloadop-kernel-dev-acb32ba3dee66d58704caeeb8c6ff95f60efdc66.zip
op-kernel-dev-acb32ba3dee66d58704caeeb8c6ff95f60efdc66.tar.gz
ipv4: reduce percpu needs for icmpmsg mibs
Reading /proc/net/snmp on a machine with a lot of cpus is very expensive (can be ~88000 us). This is because ICMPMSG MIB uses 4096 bytes per cpu, and folding values for all possible cpus can read 16 Mbytes of memory. ICMP messages are not considered as fast path on a typical server, and eventually few cpus handle them anyway. We can afford an atomic operation instead of using percpu data. This saves 4096 bytes per cpu and per network namespace. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/af_inet.c8
-rw-r--r--net/ipv4/proc.c9
2 files changed, 8 insertions, 9 deletions
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 1b5096a..b2bbcd0 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1572,9 +1572,9 @@ static __net_init int ipv4_mib_init_net(struct net *net)
sizeof(struct icmp_mib),
__alignof__(struct icmp_mib)) < 0)
goto err_icmp_mib;
- if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
- sizeof(struct icmpmsg_mib),
- __alignof__(struct icmpmsg_mib)) < 0)
+ net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
+ GFP_KERNEL);
+ if (!net->mib.icmpmsg_statistics)
goto err_icmpmsg_mib;
tcp_mib_init(net);
@@ -1598,7 +1598,7 @@ err_tcp_mib:
static __net_exit void ipv4_mib_exit_net(struct net *net)
{
- snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
+ kfree(net->mib.icmpmsg_statistics);
snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
snmp_mib_free((void __percpu **)net->mib.udp_statistics);
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 466ea8b..961eed4 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -288,7 +288,7 @@ static void icmpmsg_put(struct seq_file *seq)
count = 0;
for (i = 0; i < ICMPMSG_MIB_MAX; i++) {
- val = snmp_fold_field((void __percpu **) net->mib.icmpmsg_statistics, i);
+ val = atomic_long_read(&net->mib.icmpmsg_statistics->mibs[i]);
if (val) {
type[count] = i;
vals[count++] = val;
@@ -307,6 +307,7 @@ static void icmp_put(struct seq_file *seq)
{
int i;
struct net *net = seq->private;
+ atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;
seq_puts(seq, "\nIcmp: InMsgs InErrors");
for (i=0; icmpmibmap[i].name != NULL; i++)
@@ -319,15 +320,13 @@ static void icmp_put(struct seq_file *seq)
snmp_fold_field((void __percpu **) net->mib.icmp_statistics, ICMP_MIB_INERRORS));
for (i=0; icmpmibmap[i].name != NULL; i++)
seq_printf(seq, " %lu",
- snmp_fold_field((void __percpu **) net->mib.icmpmsg_statistics,
- icmpmibmap[i].index));
+ atomic_long_read(ptr + icmpmibmap[i].index));
seq_printf(seq, " %lu %lu",
snmp_fold_field((void __percpu **) net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
snmp_fold_field((void __percpu **) net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
for (i=0; icmpmibmap[i].name != NULL; i++)
seq_printf(seq, " %lu",
- snmp_fold_field((void __percpu **) net->mib.icmpmsg_statistics,
- icmpmibmap[i].index | 0x100));
+ atomic_long_read(ptr + (icmpmibmap[i].index | 0x100)));
}
/*
OpenPOWER on IntegriCloud