net_sched: add 64bit rate estimators
struct gnet_stats_rate_est contains u32 fields, so the bytes per second
field can wrap at 34360Mbit.
Add a new gnet_stats_rate_est64 structure to get 64bit bps/pps fields,
and switch the kernel to use this structure natively.
This structure is dumped to user space as a new attribute :
TCA_STATS_RATE_EST64
Old tc command will now display the capped bps (to 34360Mbit), instead
of wrapped values, and updated tc command will display correct
information.
Old tc command output, after patch :
eric:~# tc -s -d qd sh dev lo
qdisc pfifo 8001: root refcnt 2 limit 1000p
Sent 80868245400 bytes 1978837 pkt (dropped 0, overlimits 0 requeues 0)
rate 34360Mbit 189696pps backlog 0b 0p requeues 0
This patch carefully reorganizes "struct Qdisc" layout to get optimal
performance on SMP.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/gen_stats.c b/net/core/gen_stats.c
index ddedf21..9d3d9e7 100644
--- a/net/core/gen_stats.c
+++ b/net/core/gen_stats.c
@@ -143,18 +143,30 @@
int
gnet_stats_copy_rate_est(struct gnet_dump *d,
const struct gnet_stats_basic_packed *b,
- struct gnet_stats_rate_est *r)
+ struct gnet_stats_rate_est64 *r)
{
+ struct gnet_stats_rate_est est;
+ int res;
+
if (b && !gen_estimator_active(b, r))
return 0;
+ est.bps = min_t(u64, UINT_MAX, r->bps);
+ /* we have some time before reaching 2^32 packets per second */
+ est.pps = r->pps;
+
if (d->compat_tc_stats) {
- d->tc_stats.bps = r->bps;
- d->tc_stats.pps = r->pps;
+ d->tc_stats.bps = est.bps;
+ d->tc_stats.pps = est.pps;
}
- if (d->tail)
- return gnet_stats_copy(d, TCA_STATS_RATE_EST, r, sizeof(*r));
+ if (d->tail) {
+ res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est));
+ if (res < 0 || est.bps == r->bps)
+ return res;
+ /* emit 64bit stats only if needed */
+ return gnet_stats_copy(d, TCA_STATS_RATE_EST64, r, sizeof(*r));
+ }
return 0;
}