From patchwork Tue Jan 21 14:12:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gautam Ramakrishnan X-Patchwork-Id: 1226594 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=MIKvIhqd; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4829WL0xNcz9sRG for ; Wed, 22 Jan 2020 01:13:50 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729293AbgAUONt (ORCPT ); Tue, 21 Jan 2020 09:13:49 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:43184 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727508AbgAUONt (ORCPT ); Tue, 21 Jan 2020 09:13:49 -0500 Received: by mail-pf1-f193.google.com with SMTP id x6so1561179pfo.10 for ; Tue, 21 Jan 2020 06:13:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=bdm+4BSIcf8bgfwJebtu/elHs9NZAQK9LdWCsO2OdCI=; b=MIKvIhqda1QhkU1xKqo7Nl/6xOfd6URhhY0XVWVt3QpE8AyRu/u2ih7JuKLR9bd1cC YjqT8HERJhFQVMz33x/nAoArfqkO4NrD9/76VdQx1sDHwlKyyg5qS2mQnGr0eyisozBX VlH2otTR4W7CeEeBHpWT0zwJTYPiYmTX95/EDiqTLEVzDnw8FvaLFhLYN5pDGupTGrKF /LAzUjqfmo/Qa8avvgXVpWsukVNv9QM5wC+2YUFCmaYiX18qvpP0JdRVosif65hIc0mp LR8/gPgUhbKMv8KQk24Zy7QRtIJpqtbNyQE059Bq0pEEltz5S6bH2OCZNbOrVpFPZuxn XuPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=bdm+4BSIcf8bgfwJebtu/elHs9NZAQK9LdWCsO2OdCI=; b=q0TDYShunMV0UO3WD5mrgaAcQkJEzSkCUvoFa2ZDs92t3SsdCd2UE4YLJrzuseRB1G itHkHigtjo8YC1c/WYFbe83SNH78MbV8F8XQ3Q7rFryR7f9unZ8btDKAdfiDjrZwLO24 8w9CRTSSRD0fAa5nJXwKzR+rvF42oHJN5/cj5TtrbUyfnKRXQNcKRXgY0piKexfA4oh2 8GnlcoPoYfp552CQWXlIQYP6NtxDMSqJIDTJ9UtXbq5s/MrIUHCpD/PitNswvUjfQ6UA 1POXC/g+QArxpU8R+VUVzGqxigOua8S/eeepu8f3kSaNZYBD+l8Ch9pGc4bkGOhRb4ym OJPQ== X-Gm-Message-State: APjAAAVHelus7m87XYBfOeLMAs7DNebvfGeuAwN0jhBGtVHje1D+8Lvs 2PK9sibLgw8rzT7FT6aq4qNPcZ18ns9nJA== X-Google-Smtp-Source: APXvYqy2Fj1wyaYqHeQpi8W+uIqjvF3cF3B/fksfGddyzQYoivJI7C/GOx1sQPRVM1a3G+m9MyQ3+A== X-Received: by 2002:a62:296:: with SMTP id 144mr4804237pfc.120.1579616027186; Tue, 21 Jan 2020 06:13:47 -0800 (PST) Received: from localhost.localdomain ([223.186.212.224]) by smtp.gmail.com with ESMTPSA id y203sm44836443pfb.65.2020.01.21.06.13.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Jan 2020 06:13:46 -0800 (PST) From: gautamramk@gmail.com To: netdev@vger.kernel.org Cc: "Mohit P. Tahiliani" , Jamal Hadi Salim , "David S . Miller" , Dave Taht , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Jakub Kicinski , Stephen Hemminger , Leslie Monis , Gautam Ramakrishnan Subject: [PATCH net-next v4 09/10] net: sched: pie: export symbols to be reused by FQ-PIE Date: Tue, 21 Jan 2020 19:42:48 +0530 Message-Id: <20200121141250.26989-10-gautamramk@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200121141250.26989-1-gautamramk@gmail.com> References: <20200121141250.26989-1-gautamramk@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: "Mohit P. Tahiliani" This patch makes the drop_early(), calculate_probability() and pie_process_dequeue() functions generic enough to be used by both PIE and FQ-PIE (to be added in a future commit). The major change here is in the way the functions take in arguments. This patch exports these functions and makes FQ-PIE dependent on sch_pie. Signed-off-by: Mohit P. Tahiliani Signed-off-by: Leslie Monis Signed-off-by: Gautam Ramakrishnan --- include/net/pie.h | 9 +++ net/sched/sch_pie.c | 173 ++++++++++++++++++++++---------------------- 2 files changed, 97 insertions(+), 85 deletions(-) diff --git a/include/net/pie.h b/include/net/pie.h index 65f0e8b2193a..824b6684eeb4 100644 --- a/include/net/pie.h +++ b/include/net/pie.h @@ -124,4 +124,13 @@ static inline void pie_set_enqueue_time(struct sk_buff *skb) get_pie_cb(skb)->enqueue_time = psched_get_time(); } +bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, + struct pie_vars *vars, u32 qlen, u32 packet_size); + +void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, + struct pie_vars *vars, u32 qlen); + +void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, + u32 qlen); + #endif diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c index 637b0fcb1238..258f9c08be21 100644 --- a/net/sched/sch_pie.c +++ b/net/sched/sch_pie.c @@ -30,64 +30,65 @@ struct pie_sched_data { struct Qdisc *sch; }; -static bool drop_early(struct Qdisc *sch, u32 packet_size) +bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, + struct pie_vars *vars, u32 qlen, u32 packet_size) { - struct pie_sched_data *q = qdisc_priv(sch); u64 rnd; - u64 local_prob = q->vars.prob; + u64 local_prob = vars->prob; u32 mtu = psched_mtu(qdisc_dev(sch)); /* If there is still burst allowance left skip random early drop */ - if (q->vars.burst_time > 0) + if (vars->burst_time > 0) return false; /* If current delay is less than half of target, and * if drop prob is low already, disable early_drop */ - if ((q->vars.qdelay < q->params.target / 2) && - (q->vars.prob < MAX_PROB / 5)) + if ((vars->qdelay < params->target / 2) && + (vars->prob < MAX_PROB / 5)) return false; - /* If we have fewer than 2 mtu-sized packets, disable drop_early, + /* If we have fewer than 2 mtu-sized packets, disable pie_drop_early, * similar to min_th in RED */ - if (sch->qstats.backlog < 2 * mtu) + if (qlen < 2 * mtu) return false; /* If bytemode is turned on, use packet size to compute new * probablity. Smaller packets will have lower drop prob in this case */ - if (q->params.bytemode && packet_size <= mtu) + if (params->bytemode && packet_size <= mtu) local_prob = (u64)packet_size * div_u64(local_prob, mtu); else - local_prob = q->vars.prob; + local_prob = vars->prob; if (local_prob == 0) { - q->vars.accu_prob = 0; - q->vars.accu_prob_overflows = 0; + vars->accu_prob = 0; + vars->accu_prob_overflows = 0; } - if (local_prob > MAX_PROB - q->vars.accu_prob) - q->vars.accu_prob_overflows++; + if (local_prob > MAX_PROB - vars->accu_prob) + vars->accu_prob_overflows++; - q->vars.accu_prob += local_prob; + vars->accu_prob += local_prob; - if (q->vars.accu_prob_overflows == 0 && - q->vars.accu_prob < (MAX_PROB / 100) * 85) + if (vars->accu_prob_overflows == 0 && + vars->accu_prob < (MAX_PROB / 100) * 85) return false; - if (q->vars.accu_prob_overflows == 8 && - q->vars.accu_prob >= MAX_PROB / 2) + if (vars->accu_prob_overflows == 8 && + vars->accu_prob >= MAX_PROB / 2) return true; prandom_bytes(&rnd, 8); if (rnd < local_prob) { - q->vars.accu_prob = 0; - q->vars.accu_prob_overflows = 0; + vars->accu_prob = 0; + vars->accu_prob_overflows = 0; return true; } return false; } +EXPORT_SYMBOL_GPL(pie_drop_early); static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) @@ -100,7 +101,8 @@ static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, goto out; } - if (!drop_early(sch, skb->len)) { + if (!pie_drop_early(sch, &q->params, &q->vars, sch->qstats.backlog, + skb->len)) { enqueue = true; } else if (q->params.ecn && (q->vars.prob <= MAX_PROB / 10) && INET_ECN_set_ce(skb)) { @@ -212,26 +214,25 @@ static int pie_change(struct Qdisc *sch, struct nlattr *opt, return 0; } -static void pie_process_dequeue(struct Qdisc *sch, struct sk_buff *skb) +void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, + struct pie_vars *vars, u32 qlen) { - struct pie_sched_data *q = qdisc_priv(sch); - int qlen = sch->qstats.backlog; /* current queue size in bytes */ psched_time_t now = psched_get_time(); u32 dtime = 0; /* If dq_rate_estimator is disabled, calculate qdelay using the * packet timestamp. */ - if (!q->params.dq_rate_estimator) { - q->vars.qdelay = now - pie_get_enqueue_time(skb); + if (!params->dq_rate_estimator) { + vars->qdelay = now - pie_get_enqueue_time(skb); - if (q->vars.dq_tstamp != DTIME_INVALID) - dtime = now - q->vars.dq_tstamp; + if (vars->dq_tstamp != DTIME_INVALID) + dtime = now - vars->dq_tstamp; - q->vars.dq_tstamp = now; + vars->dq_tstamp = now; if (qlen == 0) - q->vars.qdelay = 0; + vars->qdelay = 0; if (dtime == 0) return; @@ -243,9 +244,9 @@ static void pie_process_dequeue(struct Qdisc *sch, struct sk_buff *skb) * we have enough packets to calculate the drain rate. Save * current time as dq_tstamp and start measurement cycle. */ - if (qlen >= QUEUE_THRESHOLD && q->vars.dq_count == DQCOUNT_INVALID) { - q->vars.dq_tstamp = psched_get_time(); - q->vars.dq_count = 0; + if (qlen >= QUEUE_THRESHOLD && vars->dq_count == DQCOUNT_INVALID) { + vars->dq_tstamp = psched_get_time(); + vars->dq_count = 0; } /* Calculate the average drain rate from this value. If queue length @@ -257,25 +258,25 @@ static void pie_process_dequeue(struct Qdisc *sch, struct sk_buff *skb) * in bytes, time difference in psched_time, hence rate is in * bytes/psched_time. */ - if (q->vars.dq_count != DQCOUNT_INVALID) { - q->vars.dq_count += skb->len; + if (vars->dq_count != DQCOUNT_INVALID) { + vars->dq_count += skb->len; - if (q->vars.dq_count >= QUEUE_THRESHOLD) { - u32 count = q->vars.dq_count << PIE_SCALE; + if (vars->dq_count >= QUEUE_THRESHOLD) { + u32 count = vars->dq_count << PIE_SCALE; - dtime = now - q->vars.dq_tstamp; + dtime = now - vars->dq_tstamp; if (dtime == 0) return; count = count / dtime; - if (q->vars.avg_dq_rate == 0) - q->vars.avg_dq_rate = count; + if (vars->avg_dq_rate == 0) + vars->avg_dq_rate = count; else - q->vars.avg_dq_rate = - (q->vars.avg_dq_rate - - (q->vars.avg_dq_rate >> 3)) + (count >> 3); + vars->avg_dq_rate = + (vars->avg_dq_rate - + (vars->avg_dq_rate >> 3)) + (count >> 3); /* If the queue has receded below the threshold, we hold * on to the last drain rate calculated, else we reset @@ -283,10 +284,10 @@ static void pie_process_dequeue(struct Qdisc *sch, struct sk_buff *skb) * packet is dequeued */ if (qlen < QUEUE_THRESHOLD) { - q->vars.dq_count = DQCOUNT_INVALID; + vars->dq_count = DQCOUNT_INVALID; } else { - q->vars.dq_count = 0; - q->vars.dq_tstamp = psched_get_time(); + vars->dq_count = 0; + vars->dq_tstamp = psched_get_time(); } goto burst_allowance_reduction; @@ -296,18 +297,18 @@ static void pie_process_dequeue(struct Qdisc *sch, struct sk_buff *skb) return; burst_allowance_reduction: - if (q->vars.burst_time > 0) { - if (q->vars.burst_time > dtime) - q->vars.burst_time -= dtime; + if (vars->burst_time > 0) { + if (vars->burst_time > dtime) + vars->burst_time -= dtime; else - q->vars.burst_time = 0; + vars->burst_time = 0; } } +EXPORT_SYMBOL_GPL(pie_process_dequeue); -static void calculate_probability(struct Qdisc *sch) +void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, + u32 qlen) { - struct pie_sched_data *q = qdisc_priv(sch); - u32 qlen = sch->qstats.backlog; /* queue size in bytes */ psched_time_t qdelay = 0; /* in pschedtime */ psched_time_t qdelay_old = 0; /* in pschedtime */ s64 delta = 0; /* determines the change in probability */ @@ -316,17 +317,17 @@ static void calculate_probability(struct Qdisc *sch) u32 power; bool update_prob = true; - if (q->params.dq_rate_estimator) { - qdelay_old = q->vars.qdelay; - q->vars.qdelay_old = q->vars.qdelay; + if (params->dq_rate_estimator) { + qdelay_old = vars->qdelay; + vars->qdelay_old = vars->qdelay; - if (q->vars.avg_dq_rate > 0) - qdelay = (qlen << PIE_SCALE) / q->vars.avg_dq_rate; + if (vars->avg_dq_rate > 0) + qdelay = (qlen << PIE_SCALE) / vars->avg_dq_rate; else qdelay = 0; } else { - qdelay = q->vars.qdelay; - qdelay_old = q->vars.qdelay_old; + qdelay = vars->qdelay; + qdelay_old = vars->qdelay_old; } /* If qdelay is zero and qlen is not, it means qlen is very small, @@ -342,18 +343,18 @@ static void calculate_probability(struct Qdisc *sch) * probability. alpha/beta are updated locally below by scaling down * by 16 to come to 0-2 range. */ - alpha = ((u64)q->params.alpha * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4; - beta = ((u64)q->params.beta * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4; + alpha = ((u64)params->alpha * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4; + beta = ((u64)params->beta * (MAX_PROB / PSCHED_TICKS_PER_SEC)) >> 4; /* We scale alpha and beta differently depending on how heavy the * congestion is. Please see RFC 8033 for details. */ - if (q->vars.prob < MAX_PROB / 10) { + if (vars->prob < MAX_PROB / 10) { alpha >>= 1; beta >>= 1; power = 100; - while (q->vars.prob < div_u64(MAX_PROB, power) && + while (vars->prob < div_u64(MAX_PROB, power) && power <= 1000000) { alpha >>= 2; beta >>= 2; @@ -362,14 +363,14 @@ static void calculate_probability(struct Qdisc *sch) } /* alpha and beta should be between 0 and 32, in multiples of 1/16 */ - delta += alpha * (u64)(qdelay - q->params.target); + delta += alpha * (u64)(qdelay - params->target); delta += beta * (u64)(qdelay - qdelay_old); - oldprob = q->vars.prob; + oldprob = vars->prob; /* to ensure we increase probability in steps of no more than 2% */ if (delta > (s64)(MAX_PROB / (100 / 2)) && - q->vars.prob >= MAX_PROB / 10) + vars->prob >= MAX_PROB / 10) delta = (MAX_PROB / 100) * 2; /* Non-linear drop: @@ -380,12 +381,12 @@ static void calculate_probability(struct Qdisc *sch) if (qdelay > (PSCHED_NS2TICKS(250 * NSEC_PER_MSEC))) delta += MAX_PROB / (100 / 2); - q->vars.prob += delta; + vars->prob += delta; if (delta > 0) { /* prevent overflow */ - if (q->vars.prob < oldprob) { - q->vars.prob = MAX_PROB; + if (vars->prob < oldprob) { + vars->prob = MAX_PROB; /* Prevent normalization error. If probability is at * maximum value already, we normalize it here, and * skip the check to do a non-linear drop in the next @@ -395,8 +396,8 @@ static void calculate_probability(struct Qdisc *sch) } } else { /* prevent underflow */ - if (q->vars.prob > oldprob) - q->vars.prob = 0; + if (vars->prob > oldprob) + vars->prob = 0; } /* Non-linear drop in probability: Reduce drop probability quickly if @@ -405,10 +406,10 @@ static void calculate_probability(struct Qdisc *sch) if (qdelay == 0 && qdelay_old == 0 && update_prob) /* Reduce drop probability to 98.4% */ - q->vars.prob -= q->vars.prob / 64u; + vars->prob -= vars->prob / 64; - q->vars.qdelay = qdelay; - q->vars.qlen_old = qlen; + vars->qdelay = qdelay; + vars->qlen_old = qlen; /* We restart the measurement cycle if the following conditions are met * 1. If the delay has been low for 2 consecutive Tupdate periods @@ -416,16 +417,17 @@ static void calculate_probability(struct Qdisc *sch) * 3. If average dq_rate_estimator is enabled, we have atleast one * estimate for the avg_dq_rate ie., is a non-zero value */ - if ((q->vars.qdelay < q->params.target / 2) && - (q->vars.qdelay_old < q->params.target / 2) && - q->vars.prob == 0 && - (!q->params.dq_rate_estimator || q->vars.avg_dq_rate > 0)) { - pie_vars_init(&q->vars); + if ((vars->qdelay < params->target / 2) && + (vars->qdelay_old < params->target / 2) && + vars->prob == 0 && + (!params->dq_rate_estimator || vars->avg_dq_rate > 0)) { + pie_vars_init(vars); } - if (!q->params.dq_rate_estimator) - q->vars.qdelay_old = qdelay; + if (!params->dq_rate_estimator) + vars->qdelay_old = qdelay; } +EXPORT_SYMBOL_GPL(pie_calculate_probability); static void pie_timer(struct timer_list *t) { @@ -434,7 +436,7 @@ static void pie_timer(struct timer_list *t) spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); spin_lock(root_lock); - calculate_probability(sch); + pie_calculate_probability(&q->params, &q->vars, sch->qstats.backlog); /* reset the timer to fire after 'tupdate'. tupdate is in jiffies. */ if (q->params.tupdate) @@ -523,12 +525,13 @@ static int pie_dump_stats(struct Qdisc *sch, struct gnet_dump *d) static struct sk_buff *pie_qdisc_dequeue(struct Qdisc *sch) { + struct pie_sched_data *q = qdisc_priv(sch); struct sk_buff *skb = qdisc_dequeue_head(sch); if (!skb) return NULL; - pie_process_dequeue(sch, skb); + pie_process_dequeue(skb, &q->params, &q->vars, sch->qstats.backlog); return skb; }