Patch "net_sched: gen_estimator: fix broken estimators based on percpu stats" has been added to the 4.15-stable tree

Patch "net_sched: gen_estimator: fix broken estimators based on percpu stats" has been added to the 4.15-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    net_sched: gen_estimator: fix broken estimators based on percpu stats

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net_sched-gen_estimator-fix-broken-estimators-based-on-percpu-stats.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Mar  6 19:02:56 PST 2018
From: Eric Dumazet <edumazet@google.com>
Date: Thu, 22 Feb 2018 19:45:27 -0800
Subject: net_sched: gen_estimator: fix broken estimators based on percpu stats

From: Eric Dumazet <edumazet@google.com>


[ Upstream commit a5f7add332b4ea6d4b9480971b3b0f5e66466ae9 ]

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 estimators")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/core/gen_estimator.c |    1 +
 1 file changed, 1 insertion(+)

--- 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)
 		spin_lock(e->stats_lock);
 


Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.15/doc-change-the-min-default-value-of-tcp_wmem-tcp_rmem.patch
queue-4.15/tcp-purge-write-queue-upon-rst.patch
queue-4.15/net_sched-gen_estimator-fix-broken-estimators-based-on-percpu-stats.patch
queue-4.15/tcp_bbr-better-deal-with-suboptimal-gso.patch