[PATCH RFC V2 1/2] net: Introduce helper functions to get the per cpu data

From: Raghavendra K T
Date: Wed Aug 26 2015 - 13:40:39 EST


Signed-off-by: Raghavendra K T <raghavendra.kt@xxxxxxxxxxxxxxxxxx>
---
include/net/ip.h | 10 ++++++++++
net/ipv4/af_inet.c | 41 +++++++++++++++++++++++++++--------------
2 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h
index d5fe9f2..93bf12e 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -202,10 +202,20 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)

+u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
unsigned long snmp_fold_field(void __percpu *mib, int offt);
#if BITS_PER_LONG==32
+u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+ size_t syncp_offset);
u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
#else
+static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+ size_t syncp_offset)
+{
+ return snmp_get_cpu_field(mib, cpu, offct);
+
+}
+
static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
{
return snmp_fold_field(mib, offt);
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 9532ee8..302e36b 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1448,38 +1448,51 @@ int inet_ctl_sock_create(struct sock **sk, unsigned short family,
}
EXPORT_SYMBOL_GPL(inet_ctl_sock_create);

+u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
+{
+ return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
+}
+EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
+
unsigned long snmp_fold_field(void __percpu *mib, int offt)
{
unsigned long res = 0;
int i;

for_each_possible_cpu(i)
- res += *(((unsigned long *) per_cpu_ptr(mib, i)) + offt);
+ res += snmp_get_cpu_field(mib, i, offt);
return res;
}
EXPORT_SYMBOL_GPL(snmp_fold_field);

#if BITS_PER_LONG==32

+u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+ size_t syncp_offset)
+{
+ void *bhptr;
+ struct u64_stats_sync *syncp;
+ u64 v;
+ unsigned int start;
+
+ bhptr = per_cpu_ptr(mib, cpu);
+ syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
+ do {
+ start = u64_stats_fetch_begin_irq(syncp);
+ v = *(((u64 *)bhptr) + offt);
+ } while (u64_stats_fetch_retry_irq(syncp, start));
+
+ return v;
+}
+EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
+
u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
{
u64 res = 0;
int cpu;

for_each_possible_cpu(cpu) {
- void *bhptr;
- struct u64_stats_sync *syncp;
- u64 v;
- unsigned int start;
-
- bhptr = per_cpu_ptr(mib, cpu);
- syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
- do {
- start = u64_stats_fetch_begin_irq(syncp);
- v = *(((u64 *) bhptr) + offt);
- } while (u64_stats_fetch_retry_irq(syncp, start));
-
- res += v;
+ res += snmp_get_cpu_field(mib, cpu, offct, syncp_offset);
}
return res;
}
--
1.7.11.7

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