From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl2-f12.google.com (mail-dl2-f12.google.com [74.125.229.140]) (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 A8D6D175A7F for ; Mon, 28 Sep 2026 04:34:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.229.140 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790570067; cv=none; b=VTZhuU3CRnFSP6qN9GzJUCFzcRj913IFAwuw6MncXH4p2rWZe7933njT68l4zcD4N5J5sy6qNgr61JYVgCcLh55Sqol1f16IF5UQafwE0NghlrEVIlN2lS3UA2aea7MNQ8ljvqLpsr3oLYq4cVdX6OfsHLyeWTcTM9NeBupff8s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790570067; c=relaxed/simple; bh=g3a5zgk0jvl6QiyHNyoJvGyHFF7Prr8MVyKuTY9699o=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=qKeQdqGErPUs4NT0onZBrw/Da8bApN8ifqdtIAdIhW2ZvXp7AjU4BSQPuJF5OCIbiNP3zqOWIIY9lkTWhMXOtJ13cuDbiEMxbcH7RD3+egYsl1p70EdtyyjJSzOk5XDHFSE12+XcAXpI0bejtgTBYeky5v8AoyGCysFx/hvNRgk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=PTmgM4Zz; arc=none smtp.client-ip=74.125.229.140 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PTmgM4Zz" Received: by mail-dl2-f12.google.com with SMTP id a92af1059eb24-142dd046b87so1769791c88.2 for ; Sun, 27 Sep 2026 21:34:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1790570064; x=1791174864; 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:content-type; bh=w9i4AZxPKZ+TR4dqLECza08nA+0rm81FwGX8+6DQ4hM=; b=PTmgM4ZzdvnvpQTZqxdqmDB4QbEHO/xFuS5ZFYTcqkPXkFx7RTryssqrrbpIimQagf kBNM0Q8E037Of5riWZ6S3FztQWwOXzx+kyOIQwsw7oDdXmII6c01X3xMVLBpEhuOvpwM LsxkJ1vYamlXdM26pNh0/k1Kfg9B4c1paSY1U30icsA1Dq9RaXcaJhnjFCwxxqCE5/2a b6n9LbjkcOW3l9JXRxResquuIIopPvtMn3U2KSxATu1hG+XB6eR/W3ensO9WYHUA/BlV Y3ISEyryhKURHdHKypenci8vR1Vs1ml5OAEMd12SReLqMTkd2NyLmn9Vz2RKLqQ4YRgn sufA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790570064; x=1791174864; 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:content-type; bh=w9i4AZxPKZ+TR4dqLECza08nA+0rm81FwGX8+6DQ4hM=; b=cF2eKmu1W1HGk6b1dOJe5jOCHfgfZpTd0nfbhmG+az3t/QiVCKIEGndNGM8TB7rshu 9BDZ62pzkxkAaH8rmPpPIzN63f7dceK0TbGMEZZLO03PSsvlmbkqy5xRDMKpE/SGLPiM qK62fqAA4E21rLdM+usGNKvKuy54waX9q9uyCnYbHwZwJFlAQWaJYhvWLeRs71ogIbZP 7B9pv84/Sm/Fr6rhVtMVW9zYQyQhX9LefbpVRQlsxs1cbKX42d4PBB9l0ksPF0NLaMky LlpHbt/RHXnr3b1N0BBf0tDIJsntMy8QXFPwxcj9+A0SbFM8ynNlME8vLBSIOLAFJMlw FTlg== X-Forwarded-Encrypted: i=1; AKwUvBxXSR7Z860huO78OHdlmx8N/zja4hveTiB87/Dt3rcfhU5u3EqW52oMVGBxTzhIXGUntGgp6pcQ8Tplywc=@vger.kernel.org X-Gm-Message-State: AFuF++muii1x0Aq3O/4yHRytNM4rVcsdHpNygvM7gAf/5XQS4LNohlq3 8mrMtT6wWFe7HIkTIU1U87hkA42UK9ilhcphanZ42azjGipODOW2Ze8s X-Gm-Gg: AYBFou2vPsXvZZF3IoGClKFvvRzMgGWzA0dJSM7Lf06YR/fRQtiBI7qXVo/iqrLu/vo vLF+DzHaZCwxWjtRR8VuBjrtVqTU8y1ym/D82GYcOSJjhZsoPAudrOH6xH/qSVYDRtjwtMlauEy DbCJIKkw1Ns5h2vUWnmaDrgrsom/UPPVJvYCLCaFgovwb4PxbfHKOfnHKmkadbL5aN78vmtz+yj 8C6wsAen7hKeWzqJ3kpDbqvFjDkfPKViOVU6LRYlB9GUJdVDXGCgKuKd0b5zP6BZQkMvIWmZHNM u5ye0Rx85YyDKTP1HgQeLv7GiC1UQA2komyt5ViAnDtbORX+xOQ+8p7ZMJJB7PEbmHbeGf2CDmB Je7Qx16nWTbi8PhK9hl31EnnbLatLKw5ujMe5poVgQcCd1j0rAdoCsJfBmcKgruQ43JO7p4vsfA KbDmaTXPYr+V4dY1OZS4oXRn8MlHxZY7pEy2qaJnTSXTQ/i+ACzR//TyasLvtFo6cxBUV7KKviY Qg5iE2tw3LdlQBY5DkBkB0qgUB5KmwHsJbSnC3vZhoOwLH5K4QEC2PsYg6MAabiW/ZGE7CtXhpe ws2LhvI= X-Received: by 2002:a05:7022:ea8b:b0:144:eaa7:2765 with SMTP id a92af1059eb24-146ce67f3c1mr9015303c88.18.1790570063660; Sun, 27 Sep 2026 21:34:23 -0700 (PDT) Received: from Inspiron-14-5420.. ([2402:e280:21c6:671:571a:2a:d409:bce3]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-145adbcd1bcsm27921045c88.14.2026.09.27.21.34.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 27 Sep 2026 21:34:23 -0700 (PDT) From: "Hemendra M. Naik" To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, jiri@resnulli.us, jhs@mojatatu.com, shuah@kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, vishy0777@gmail.com, tahiliani@nitk.edu.in, "Hemendra M. Naik" Subject: [PATCH net-next v9 1/3] net/sched: sch_fq_pie: add per-flow statistics via class ops Date: Mon, 28 Sep 2026 10:03:56 +0530 Message-Id: <20260928043358.6866-2-hemendranaik@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260928043358.6866-1-hemendranaik@gmail.com> References: <20260928043358.6866-1-hemendranaik@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit FQ-PIE schedules independent PIE controllers per flow but exposes no per-flow AQM state. Without class-level statistics there is no way to observe the per-flow drop probability, queue delay, deficit or dequeue rate from userspace. Extend tc_fq_pie_xstats with a type discriminator and tc_fq_pie_cl_stats for per-flow metrics. The nine existing __u32 counters keep their offsets, type is appended at offset 36 and class_stats follows it, growing the structure from 36 to 64 bytes. Wire up fq_pie_class_ops with walk, dump, and dump_stats only so that 'tc -s class show' reports per-flow state (prob, delay, deficit, avg_dq_rate, dq_rate_estimating). Filter attachment callbacks (.tcf_block, .bind_tcf, .unbind_tcf) are omitted on purpose. Signed-off-by: Hemendra M. Naik Signed-off-by: Vishal Kamath Signed-off-by: Mohit P. Tahiliani --- include/uapi/linux/pkt_sched.h | 17 +++++++ net/sched/sch_fq_pie.c | 88 +++++++++++++++++++++++++++++++++- 2 files changed, 104 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index 490efd288526..fef848eaaab2 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -953,6 +953,21 @@ enum { }; #define TCA_FQ_PIE_MAX (__TCA_FQ_PIE_MAX - 1) +enum { + TCA_FQ_PIE_XSTATS_QDISC, + TCA_FQ_PIE_XSTATS_CLASS, +}; + +struct tc_fq_pie_cl_stats { + __u64 prob; /* current probability */ + __u32 delay; /* current delay in microseconds */ + __s32 deficit; /* number of remaining byte credits */ + __u32 avg_dq_rate; /* current average dq_rate in + * bytes/second + */ + __u32 dq_rate_estimating; /* is avg_dq_rate being calculated? */ +}; + struct tc_fq_pie_xstats { __u32 packets_in; /* total number of packets enqueued */ __u32 dropped; /* packets dropped due to fq_pie_action */ @@ -963,6 +978,8 @@ struct tc_fq_pie_xstats { __u32 new_flows_len; /* count of flows in new list */ __u32 old_flows_len; /* count of flows in old list */ __u32 memory_usage; /* total memory across all queues */ + __u32 type; + struct tc_fq_pie_cl_stats class_stats; }; /* CBS */ diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c index 5982847df8f8..8cd99ff40d0a 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -511,7 +511,11 @@ static int fq_pie_dump(struct Qdisc *sch, struct sk_buff *skb) static int fq_pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d) { struct fq_pie_sched_data *q = qdisc_priv(sch); - struct tc_fq_pie_xstats st = { 0 }; + + struct tc_fq_pie_xstats st = { + .type = TCA_FQ_PIE_XSTATS_QDISC, + }; + struct list_head *pos; sch_tree_lock(sch); @@ -563,7 +567,89 @@ static void fq_pie_destroy(struct Qdisc *sch) kvfree(q->flows); } +static struct Qdisc *fq_pie_leaf(struct Qdisc *sch, unsigned long arg) +{ + return NULL; +} + +static unsigned long fq_pie_find(struct Qdisc *sch, u32 classid) +{ + return 0; +} + +static int fq_pie_dump_class(struct Qdisc *sch, unsigned long cl, + struct sk_buff *skb, struct tcmsg *tcm) +{ + tcm->tcm_handle |= TC_H_MIN(cl); + return 0; +} + +static int fq_pie_dump_class_stats(struct Qdisc *sch, unsigned long cl, + struct gnet_dump *d) +{ + struct fq_pie_sched_data *q = qdisc_priv(sch); + struct gnet_stats_queue qs = { 0 }; + struct tc_fq_pie_xstats xstats; + u32 idx = cl - 1; + + if (idx < q->flows_cnt) { + const struct fq_pie_flow *flow = &q->flows[idx]; + + memset(&xstats, 0, sizeof(xstats)); + xstats.type = TCA_FQ_PIE_XSTATS_CLASS; + xstats.class_stats.prob = + READ_ONCE(flow->vars.prob) << BITS_PER_BYTE; + xstats.class_stats.delay = + div_u64(PSCHED_TICKS2NS(READ_ONCE(flow->vars.qdelay)), + NSEC_PER_USEC); + xstats.class_stats.deficit = READ_ONCE(flow->deficit); + xstats.class_stats.dq_rate_estimating = + READ_ONCE(q->p_params.dq_rate_estimator); + + if (xstats.class_stats.dq_rate_estimating) { + xstats.class_stats.avg_dq_rate = + ((u64)READ_ONCE(flow->vars.avg_dq_rate) + * PSCHED_TICKS_PER_SEC) >> PIE_SCALE; + } + + qs.qlen = READ_ONCE(flow->qlen); + qs.backlog = READ_ONCE(flow->backlog); + } + if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) + return -1; + if (idx < q->flows_cnt) + return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); + return 0; +} + +static void fq_pie_walk(struct Qdisc *sch, struct qdisc_walker *arg) +{ + struct fq_pie_sched_data *q = qdisc_priv(sch); + unsigned int i; + + if (arg->stop) + return; + + for (i = 0; i < q->flows_cnt; i++) { + if (list_empty(&q->flows[i].flowchain)) { + arg->count++; + continue; + } + if (!tc_qdisc_stats_dump(sch, i + 1, arg)) + break; + } +} + +static const struct Qdisc_class_ops fq_pie_class_ops = { + .leaf = fq_pie_leaf, + .find = fq_pie_find, + .dump = fq_pie_dump_class, + .dump_stats = fq_pie_dump_class_stats, + .walk = fq_pie_walk, +}; + static struct Qdisc_ops fq_pie_qdisc_ops __read_mostly = { + .cl_ops = &fq_pie_class_ops, .id = "fq_pie", .priv_size = sizeof(struct fq_pie_sched_data), .enqueue = fq_pie_qdisc_enqueue, -- 2.34.1