From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (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 0566B2DC792 for ; Wed, 2 Sep 2026 03:53:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788321202; cv=none; b=eqiCYyDzd5w4aB1adyhToF4DDamrTT+G3ucsR0ujceSoFddlHHzl+Ve26J5YclPw/St24V6LAFifccLtcpUgjM8XQvNMDNOWMZoZMFjVxXpPqQHs+G62LhLBMvzV5BUX95/tqsYCT4YHWY6smDC5rSrBZAUdGtOI7eL89cfrU/Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788321202; c=relaxed/simple; bh=DWyXtGKCFcLcmBruy07T0qhMMySVP7dfZtEM8AJJROY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=GyX2bk8jOcuaw69zroxw7N14Bv1nENsW20yfgU4BEA+WP8MUisVbtr/so3MClCUVwNl5coC8gNdwu+hr2tc6hK8C/vv54ZMdMvoJABJ9AuAenHO4mePVvnn1q+6ett63UXbSi6eN4AyhLPOyoNPPWBLJPR7CK0+/OyaRk5TvUDc= 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=ONeMNfDy; arc=none smtp.client-ip=209.85.214.182 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="ONeMNfDy" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-2ceab75934dso6591595ad.2 for ; Tue, 01 Sep 2026 20:53:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788321200; x=1788926000; 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=Hg+2sotZuSoFWu3kV8aYbXJlZcYn1u1/mg6yUnnLhl0=; b=ONeMNfDyERvTOnvQEbT5l+gC8IAv1k+/AUx4FY65+JTJ1n52FVwcPoPRq95ooO5a51 uRMrwWpMR5muiY5rbI9k0nZKw8B62GEw5E8xDsKjeOAmU/9Z4orzn647Ri50GJH6Q9Ya 9kJlfftlAOd0C0nXfXIMwzLMCGj9uRxx5ia5/Nks0KcbeqfsBXRFu0ICPvU8c/rEErGu odAo8T0x1nIKChUFoMrLeFiDsxhMkbup4l1mRnIBKYMzz3AUZBix4pOz+M1DjO3SaDn8 XFFZvx8PiNOM/SFvTbHGlEuVB/A9Ds77V4LGT4THJAeCwUBXHovidmZaFETShxvi98P1 0Efw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788321200; x=1788926000; 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=Hg+2sotZuSoFWu3kV8aYbXJlZcYn1u1/mg6yUnnLhl0=; b=XfLGl1yiNck4VQ0xXT1GWWUugWbLiqdDx8yoi80LG1CMGwVRpmIbEiH9xqIJ4fAL7C VdZXmGGIH8gXnuh4UKkSxmvLtMX9jQVp0i2O9vYP5XIQtNPShtrk5VtLR9FbYbghwroH o0Nqlbo2nwavtE4amlsePiVAsPdF2cUpGEpyWW0kEgSI+hnhT2YyK4NiuZb1cblzZ+wy olqNNtq/qWorTcRhQeyTyFHZCAESAIWfMBUhv5cqlv5Jf3wY80fZfdGcPaY0/dU15ud6 SKxCXJVMXmV94IHA7XMPfQ8O8udz7UoTHS6P2NABwKld/7Bnz5L/aOhJnZ4nJuobTbj0 IPVw== X-Gm-Message-State: AFuF++m6Z6AkOxRsMOer4WJgjeBPxeYc1IHR8dglx7Px4Lj6SQ7AFqrh 0wNiEJpDdFPs3fbD/EHUGuVbjC4FmB6OntkiKUK4R+LDCd5ms0qvv7+rZu+y8vQ+ X-Gm-Gg: AR+sD13FAvETa7oGG6GHtLBgRpaWD/tIW15leUkesS/28Dq43SFIgxw88mMitQ0fKGE aM0M6lVOAlZvfzCll9zIfKVOdIXoPZP0h3OyQAllFAl3/14cHNnO2jPGhhpTBIildBS/yKBxDP7 vLIBEpipnD4XZOAXFSnBll4ZTWMBUioIGlY1wCUrVCyut0lwm/HpnumZa5CIVGnwwhE7T1tq/J8 4EKZl6tpunjW0N7uHgaLcUdgHuBnkVXdi+msUlhQ8AzPpazkY2t8qykRt/2l/u2xhQWqs+fsweE 7pm8pDYMskdzeuryQw88Sg2meGaC2abrKNCtK45lCGQavAeMYQwt/NEuCUA2BZfobBuOipuQmJr JXu+rcOCrhA/V+qc45ixkvYLwhyXlUdm94tgdp++r8UJw6aRI98IHSQLij0gviCcntZxx6FX2UY JxUM886fjzPlIE0Upj8PP0zUCfgYtFqYtNCFMLwzypL90B6y2/4tSUSDi4ht92g+fQ/86+PbCVj oaHbZR19V5zw4W5tLvIbzeJWK7TtXI7Fdda+AE8mjDeZQoJlvSBHH43AO9cWmmw X-Received: by 2002:a17:903:1a68:b0:2d8:d4d0:7932 with SMTP id d9443c01a7336-2daec7a260dmr24412985ad.22.1788321200217; Tue, 01 Sep 2026 20:53:20 -0700 (PDT) Received: from Inspiron-14-5420.. ([2402:e280:21c6:671:5fdf:d463:f07:1882]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-32f07b7987csm2502377eec.16.2026.09.01.20.53.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Sep 2026 20:53:19 -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 v5 1/3] net/sched: sch_fq_pie: add per-flow statistics via class ops Date: Wed, 2 Sep 2026 09:22:29 +0530 Message-Id: <20260902035231.81866-2-hemendranaik@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260902035231.81866-1-hemendranaik@gmail.com> References: <20260902035231.81866-1-hemendranaik@gmail.com> Precedence: bulk X-Mailing-List: netdev@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. Append type and class_stats after the nine existing qdisc counters so qdisc xstats offsets stay compatible with the flat struct fq_pie already shipped. 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: this series targets exporting statistics, not making fq_pie filter-capable. Limit flows to [1..65535] so every per-flow class handle fits in a 16-bit TC minor (TC_H_MIN wraps at 65536). Signed-off-by: Hemendra M. Naik Signed-off-by: Vishal Kamath Signed-off-by: Mohit P. Tahiliani --- include/uapi/linux/pkt_sched.h | 19 +++++++ net/sched/sch_fq_pie.c | 90 ++++++++++++++++++++++++++++++++-- 2 files changed, 106 insertions(+), 3 deletions(-) diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index 490efd288526..c6373f410d11 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 +978,9 @@ 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 069e1facd413..4e3eb8329d99 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -310,9 +310,9 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt, goto flow_error; } q->flows_cnt = nla_get_u32(tb[TCA_FQ_PIE_FLOWS]); - if (!q->flows_cnt || q->flows_cnt > 65536) { + if (!q->flows_cnt || q->flows_cnt > 65535) { NL_SET_ERR_MSG_MOD(extack, - "Number of flows must range in [1..65536]"); + "Number of flows must range in [1..65535]"); goto flow_error; } } @@ -509,7 +509,9 @@ 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); @@ -561,7 +563,89 @@ 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 = + ((u32)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 = + 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