In several places the same code is used to populate rtnl_link_stats64
fields with data from pcpu_sw_netstats. Therefore factor out this code
to a new function dev_fetch_sw_netstats().
Signed-off-by: Heiner Kallweit <[email protected]>
---
include/linux/netdevice.h | 2 ++
net/core/dev.c | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 38 insertions(+)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a0df43b13..ca4736349 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4495,6 +4495,8 @@ struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
struct rtnl_link_stats64 *storage);
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
const struct net_device_stats *netdev_stats);
+void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
+ struct pcpu_sw_netstats __percpu *netstats);
extern int netdev_max_backlog;
extern int netdev_tstamp_prequeue;
diff --git a/net/core/dev.c b/net/core/dev.c
index 7d18560b2..ba91bf16b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10323,6 +10323,42 @@ struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
}
EXPORT_SYMBOL(dev_get_stats);
+/**
+ * dev_fetch_sw_netstats - get per-cpu network device statistics
+ * @s: place to store stats
+ * @netstats: per-cpu network stats to read from
+ *
+ * Read per-cpu network statistics and populate the related fields in s.
+ */
+void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
+ struct pcpu_sw_netstats __percpu *netstats)
+{
+ int cpu;
+
+ if (IS_ERR_OR_NULL(netstats))
+ return;
+
+ for_each_possible_cpu(cpu) {
+ struct pcpu_sw_netstats *stats, tmp;
+ unsigned int start;
+
+ stats = per_cpu_ptr(netstats, cpu);
+ do {
+ start = u64_stats_fetch_begin_irq(&stats->syncp);
+ tmp.rx_packets = stats->rx_packets;
+ tmp.rx_bytes = stats->rx_bytes;
+ tmp.tx_packets = stats->tx_packets;
+ tmp.tx_bytes = stats->tx_bytes;
+ } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
+
+ s->rx_packets += tmp.rx_packets;
+ s->rx_bytes += tmp.rx_bytes;
+ s->tx_packets += tmp.tx_packets;
+ s->tx_bytes += tmp.tx_bytes;
+ }
+}
+EXPORT_SYMBOL(dev_fetch_sw_netstats);
+
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
{
struct netdev_queue *queue = dev_ingress_queue(dev);
--
2.28.0
On Sun, 11 Oct 2020 21:36:43 +0200
Heiner Kallweit <[email protected]> wrote:
> +void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
> + struct pcpu_sw_netstats __percpu *netstats)
netstats is unmodified, should it be const?
> +{
> + int cpu;
> +
> + if (IS_ERR_OR_NULL(netstats))
> + return;
Any code calling this with a null pointer is broken/buggy, please don't
ignore that.
On 11.10.2020 21:54, Stephen Hemminger wrote:
> On Sun, 11 Oct 2020 21:36:43 +0200
> Heiner Kallweit <[email protected]> wrote:
>
>> +void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
>> + struct pcpu_sw_netstats __percpu *netstats)
>
> netstats is unmodified, should it be const?
>
>> +{
>> + int cpu;
>> +
>> + if (IS_ERR_OR_NULL(netstats))
>> + return;
>
> Any code calling this with a null pointer is broken/buggy, please don't
> ignore that.
>
Thanks, I'll consider both points in a v2.
On Sun, 11 Oct 2020 21:36:43 +0200 Heiner Kallweit wrote:
> In several places the same code is used to populate rtnl_link_stats64
> fields with data from pcpu_sw_netstats. Therefore factor out this code
> to a new function dev_fetch_sw_netstats().
>
> Signed-off-by: Heiner Kallweit <[email protected]>
> +/**
> + * dev_fetch_sw_netstats - get per-cpu network device statistics
> + * @s: place to store stats
> + * @netstats: per-cpu network stats to read from
> + *
> + * Read per-cpu network statistics and populate the related fields in s.
in @s?
> + */
> +void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
> + struct pcpu_sw_netstats __percpu *netstats)
> +}
> +EXPORT_SYMBOL(dev_fetch_sw_netstats);
Your pick, but _GPL would be fine too even if most exports here are
non-GPL-exclusive.