loopback: use u64_stats_sync infrastructure
Commit 6b10de38f0ef (loopback: Implement 64bit stats on 32bit arches)
introduced 64bit stats in loopback driver, using a private seqcount and
private helpers.
David suggested to introduce a generic infrastructure, added in (net:
Introduce u64_stats_sync infrastructure)
This patch reimplements loopback 64bit stats using the u64_stats_sync
infrastructure.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 09334f8..4dd0510 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -58,53 +58,15 @@
#include <linux/tcp.h>
#include <linux/percpu.h>
#include <net/net_namespace.h>
+#include <linux/u64_stats_sync.h>
struct pcpu_lstats {
- u64 packets;
- u64 bytes;
-#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
- seqcount_t seq;
-#endif
- unsigned long drops;
+ u64 packets;
+ u64 bytes;
+ struct u64_stats_sync syncp;
+ unsigned long drops;
};
-#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
-static void inline lstats_update_begin(struct pcpu_lstats *lstats)
-{
- write_seqcount_begin(&lstats->seq);
-}
-static void inline lstats_update_end(struct pcpu_lstats *lstats)
-{
- write_seqcount_end(&lstats->seq);
-}
-static void inline lstats_fetch_and_add(u64 *packets, u64 *bytes, const struct pcpu_lstats *lstats)
-{
- u64 tpackets, tbytes;
- unsigned int seq;
-
- do {
- seq = read_seqcount_begin(&lstats->seq);
- tpackets = lstats->packets;
- tbytes = lstats->bytes;
- } while (read_seqcount_retry(&lstats->seq, seq));
-
- *packets += tpackets;
- *bytes += tbytes;
-}
-#else
-static void inline lstats_update_begin(struct pcpu_lstats *lstats)
-{
-}
-static void inline lstats_update_end(struct pcpu_lstats *lstats)
-{
-}
-static void inline lstats_fetch_and_add(u64 *packets, u64 *bytes, const struct pcpu_lstats *lstats)
-{
- *packets += lstats->packets;
- *bytes += lstats->bytes;
-}
-#endif
-
/*
* The higher levels take care of making this non-reentrant (it's
* called with bh's disabled).
@@ -126,10 +88,10 @@
len = skb->len;
if (likely(netif_rx(skb) == NET_RX_SUCCESS)) {
- lstats_update_begin(lb_stats);
+ u64_stats_update_begin(&lb_stats->syncp);
lb_stats->bytes += len;
lb_stats->packets++;
- lstats_update_end(lb_stats);
+ u64_stats_update_end(&lb_stats->syncp);
} else
lb_stats->drops++;
@@ -148,10 +110,18 @@
pcpu_lstats = (void __percpu __force *)dev->ml_priv;
for_each_possible_cpu(i) {
const struct pcpu_lstats *lb_stats;
+ u64 tbytes, tpackets;
+ unsigned int start;
lb_stats = per_cpu_ptr(pcpu_lstats, i);
- lstats_fetch_and_add(&packets, &bytes, lb_stats);
+ do {
+ start = u64_stats_fetch_begin(&lb_stats->syncp);
+ tbytes = lb_stats->bytes;
+ tpackets = lb_stats->packets;
+ } while (u64_stats_fetch_retry(&lb_stats->syncp, start));
drops += lb_stats->drops;
+ bytes += tbytes;
+ packets += tpackets;
}
stats->rx_packets = packets;
stats->tx_packets = packets;