From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dy1-f180.google.com (mail-dy1-f180.google.com [74.125.82.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0A8AB215F42 for ; Sat, 2 May 2026 00:18:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777681135; cv=none; b=l9+NbITTrucJ0Nj7bFrw67YG/vhjqorkt6NOGri5MfiBPqAhDROmFcYYUppjOPMlVOs2a+PU/wILso5L0VT7v92nwQtUFRvByRUbtpVF3p4xXywTr07I+nWfylr66WekTcTwJ/E4BfcfxqUuXalcN01uTwFVOPa0f7fwtxHAZ1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777681135; c=relaxed/simple; bh=03X85ak6aFDdg+QjaCGxAhcr6g7GQHx1izWx1mPpeVs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hwHArrm0aIpvodpJd39d/CFTzRHN2QF+vMhJa20uA5scKN27+sQhlkdWJpsVW+hlgtbNZ6FwXIOBANytA45pQJjHGVeIsT2ea84yWX4qAuXDufxiwM63jbsMiiLWEU5WGXPN0ZaeMTaqgq2z1DHi7ZszjlIJNjmgIaEQ1H2vG9M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=networkplumber.org; spf=pass smtp.mailfrom=networkplumber.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20251104.gappssmtp.com header.i=@networkplumber-org.20251104.gappssmtp.com header.b=yzpNPLtq; arc=none smtp.client-ip=74.125.82.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=networkplumber.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=networkplumber.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20251104.gappssmtp.com header.i=@networkplumber-org.20251104.gappssmtp.com header.b="yzpNPLtq" Received: by mail-dy1-f180.google.com with SMTP id 5a478bee46e88-2eadb000b8cso4580511eec.0 for ; Fri, 01 May 2026 17:18:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20251104.gappssmtp.com; s=20251104; t=1777681133; x=1778285933; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=+Fo0R2O/NW/7EIp8nuaTunWiLomiuWqyBBw33q7U+4o=; b=yzpNPLtqgJJy+KW5URw0CWZ2QZYyjwLjY+kTOW10+9stMwlXf/On7fZCyX9uaDhWCk YihwUfbFNUO+HGNOjSUjNtg1kJ+uYiBx7VTvKqTgZXb8qrYGz174lNdAWI5G42Zxksl0 YDOGrk9qieuLJFJk38J3FJqmour7Rf2vsbmPnxs7uTvdkj4XUHnB4+XAZDxYR9Ym5ktz xis2j652g0mDxMCWJSdJdSMrh3bGTwgzlIwL8sPFvA7Tjs8dzmYvB97sxLm+dLx0EQbB SoCeW3SScJaHcRQlraheI4nHXWGXlDXuZ6p+ip5/MDb8jL45pDcu5xDc9nUSNuu9U/Pc gauw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777681133; x=1778285933; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=+Fo0R2O/NW/7EIp8nuaTunWiLomiuWqyBBw33q7U+4o=; b=TSn5yviOfrHc+xxpbqyx/7dpbc80998fm+IBIlrfAme5rg87jZD9i9rfwGCW4mH8Gb qiCpiHjfnrwbnAX8GgBScwvz383jzEDq3B/GwOGRoj+ZcuXAu9g1WRhjooV9QkX2nNu5 kTYRzdmj6DNjn0WbfTL9KLKgUTIubjGTWEy/HnJfvtc26MRdmDa6tqmJT0z/MinYrcns ZHfVmNdSlpy8f9TmYf2HQuVmGvKXo9BJcppqTPGNTimn68LdF+CwgP2CnvhE/f9NJwno /TspXHQ92JuxUvGlpS+6MKRTbChZGAfN7Xx/uBpbJwUs0PgI5r6pwN7HZyqjHViH7PrQ fzLQ== X-Forwarded-Encrypted: i=1; AFNElJ+D4nUbHe1Fg0KwERE612yI7n4pF3X0tAoqZNEsV4CXt3g52CdxTBydaduABPQnuAIpmwScTV3VVRpO3OE=@vger.kernel.org X-Gm-Message-State: AOJu0Yz8yHLmqgt6/1Z81tidvwpeUiP1kgq3NOvDP5SeK9YJjcH/iE/3 kUCX5YKXE6ex75POdXpVRccCnjJqZK4HKCMWLIxQd+sEXLqD4KfRBDTxuzcjjZClMog= X-Gm-Gg: AeBDieu4Um4ggDXEPN5E0UA+dkSxWjbKEopTPRcfGOdj1B1M5wMoC6DwutHp6Hk21eU iwSlzhsusU5AZxS+njaQkD5GJ3GB2l2OqkB2YdzM10HErMu5dXXGWNOfVN63sWA05p/lUCLbVjD Qh/3URRSzKGbo9QDdXClztjocqb1pTP9Ut5qijfxKIl+7GfUZVTeO7ON35Kj/ZP+AFuZWNc3JR6 kHK2twKdEFoXghmCZrkgGVThOubjH/YF4vfuhlNw/RqaFSC2YF16sgXLrlAwAk7/bnQt1VmdXz5 7MulTHWrtmDu5NS7S8ajYpZq9Irqq0lmivzd7Us+QSZUFsCFoNEyBQ6lyWZuDCFtzAZKDQIBGa1 IILR2aJdMKUAMC7JGB9RUeS7Axne4+nWZccOsYesZXpfRlJ4urAqIOx0Piu4Bw/hVWLhU3L3Knk IDg3kVBeuUE7v1rEZ465zL/wWS5oC2zxEG2m4Z7+EJ3ic= X-Received: by 2002:a05:7300:690a:b0:2e7:120:137b with SMTP id 5a478bee46e88-2efb4f2c0f8mr695595eec.0.1777681133126; Fri, 01 May 2026 17:18:53 -0700 (PDT) Received: from phoenix.lan ([104.202.41.210]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-2ee3b29b2e0sm6419484eec.16.2026.05.01.17.18.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 May 2026 17:18:52 -0700 (PDT) From: Stephen Hemminger To: netdev@kernel.org Cc: jhs@mojatatu.com, jiri@resnulli.us, Stephen Hemminger , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , netdev@vger.kernel.org (open list:TC subsystem), linux-kernel@vger.kernel.org (open list) Subject: [PATCH net-next 4/4] netem: add per-impairment extended statistics Date: Fri, 1 May 2026 17:17:12 -0700 Message-ID: <20260502001844.19107-5-stephen@networkplumber.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260502001844.19107-1-stephen@networkplumber.org> References: <20260502001844.19107-1-stephen@networkplumber.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Adds new counters that keep track of when netem applied impairments (delay, loss, corruption, duplication, reordering). Add a struct tc_netem_xstats reported via TCA_STATS_APP so that userspace (tc -s qdisc show) can display per-impairment counters. Use the WRITE_ONCE/READ_ONCE pattern to allow for lockless qdisc usage. Accompanying iproute2 change is submitted separately. Signed-off-by: Stephen Hemminger --- include/uapi/linux/pkt_sched.h | 9 ++++++++ net/sched/sch_netem.c | 40 +++++++++++++++++++++++++++++++--- 2 files changed, 46 insertions(+), 3 deletions(-) diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index 66e8072f44df..1c84c8076e22 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -569,6 +569,15 @@ struct tc_netem_gemodel { #define NETEM_DIST_SCALE 8192 #define NETEM_DIST_MAX 16384 +struct tc_netem_xstats { + __u64 delayed; /* packets delayed */ + __u64 dropped; /* packets dropped by loss model */ + __u64 corrupted; /* packets with bit errors injected */ + __u64 duplicated; /* duplicate packets generated */ + __u64 reordered; /* packets sent out of order */ + __u64 ecn_marked; /* packets ECN CE-marked (not dropped)*/ +}; + /* DRR */ enum { diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 116e96d79ddf..c871c7a3b117 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -152,6 +152,14 @@ struct netem_sched_data { } slot; struct disttable *slot_dist; + + /* Per-impairment counters */ + __u64 delayed; + __u64 dropped; + __u64 corrupted; + __u64 duplicated; + __u64 reordered; + __u64 ecn_marked; }; /* Time stamp put into socket buffer control block @@ -459,17 +467,23 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch, skb->prev = NULL; /* Random duplication */ - if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor, &q->prng)) + if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor, &q->prng)) { ++count; + WRITE_ONCE(q->duplicated, q->duplicated + 1); + } /* Drop packet? */ if (loss_event(q)) { - if (q->ecn && INET_ECN_set_ce(skb)) + if (q->ecn && INET_ECN_set_ce(skb)) { qdisc_qstats_drop(sch); /* mark packet */ - else + WRITE_ONCE(q->ecn_marked, q->ecn_marked + 1); + } else { --count; + } } + if (count == 0) { + WRITE_ONCE(q->dropped, q->dropped + 1); qdisc_qstats_drop(sch); __qdisc_drop(skb, to_free); return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; @@ -495,6 +509,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch, * do it now in software before we mangle it. */ if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor, &q->prng)) { + WRITE_ONCE(q->corrupted, q->corrupted + 1); if (skb_is_gso(skb)) { skb = netem_segment(skb, sch, to_free); if (!skb) @@ -600,12 +615,15 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch, cb->time_to_send = now + delay; ++q->counter; + WRITE_ONCE(q->delayed, q->delayed + 1); + tfifo_enqueue(skb, sch); } else { /* * Do re-ordering by putting one out of N packets at the front * of the queue. */ + WRITE_ONCE(q->reordered, q->reordered + 1); cb->time_to_send = ktime_get_ns(); q->counter = 0; @@ -1344,6 +1362,21 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) return -1; } +static int netem_dump_stats(struct Qdisc *sch, struct gnet_dump *d) +{ + struct netem_sched_data *q = qdisc_priv(sch); + struct tc_netem_xstats st = { + .delayed = READ_ONCE(q->delayed), + .dropped = READ_ONCE(q->dropped), + .corrupted = READ_ONCE(q->corrupted), + .duplicated = READ_ONCE(q->duplicated), + .reordered = READ_ONCE(q->reordered), + .ecn_marked = READ_ONCE(q->ecn_marked), + }; + + return gnet_stats_copy_app(d, &st, sizeof(st)); +} + static int netem_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, struct tcmsg *tcm) { @@ -1406,6 +1439,7 @@ static struct Qdisc_ops netem_qdisc_ops __read_mostly = { .destroy = netem_destroy, .change = netem_change, .dump = netem_dump, + .dump_stats = netem_dump_stats, .owner = THIS_MODULE, }; MODULE_ALIAS_NET_SCH("netem"); -- 2.53.0