From: Eric Dumazet <>

pfifo_fast got percpu stats lately, uncovering a bug I introduced last
year in linux-4.10.

I missed the fact that we have to clear our temporary storage
before calling __gnet_stats_copy_basic() in the case of percpu stats.

Without this fix, rate estimators (tc qd replace dev xxx root est 1sec
4sec pfifo_fast) are utterly broken.

Fixes: 1c0d32fde5bd ("net_sched: gen_estimator: complete rewrite of rate 
Signed-off-by: Eric Dumazet <>
v2: Perform the zeroing in est_fetch_counters() instead of caller(s)

 net/core/gen_estimator.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c
--- a/net/core/gen_estimator.c
+++ b/net/core/gen_estimator.c
@@ -66,6 +66,7 @@ struct net_rate_estimator {
 static void est_fetch_counters(struct net_rate_estimator *e,
                               struct gnet_stats_basic_packed *b)
+       memset(b, 0, sizeof(*b));
        if (e->stats_lock)

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