From patchwork Wed Mar 4 18:55:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leslie Monis X-Patchwork-Id: 1249181 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=DXq2OLbn; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48XjlM71qdz9sPR for ; Thu, 5 Mar 2020 05:56:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388117AbgCDS4P (ORCPT ); Wed, 4 Mar 2020 13:56:15 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:39857 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726561AbgCDS4O (ORCPT ); Wed, 4 Mar 2020 13:56:14 -0500 Received: by mail-pg1-f196.google.com with SMTP id s2so1422640pgv.6 for ; Wed, 04 Mar 2020 10:56:14 -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=Ww6PVJ28DVfom+lsskPik3ecq8bDZeuZCLwJlAjQfg0=; b=DXq2OLbnyITD7Q9+8+kOx4Bv/9NUbB54JkNDq+6ydoYcgMrDmcO3QRURD5C0/Lg/uZ ZMlkTnKEWZ4aRAcuTcFvs9ORn54OLRchJDUdfWZTCfV+YV0VRrxci/JlY8M6rpUh9TsZ C4yKGWJcD6M+KC17ZCDI9ck7fArW4ziJES+CscRy6jCm3HDJn/SCKQcbrUkA1Fs4Wynu w8/GhOepCD81Bw5zbM1ImFYFm+xY+hQUzxZllVe1juGkTmCiuf/ZdR9U8z/YMrVU4OWr 8K6fkbQsH5Bea6NvczFWoNdeOnGQUqY5tu3A+H8W0aJPgGl+ourkECgCfb+4WsoHpLo6 0bTA== 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=Ww6PVJ28DVfom+lsskPik3ecq8bDZeuZCLwJlAjQfg0=; b=I8xjKEQND6XrJZ4ILl5OaOrYBP6MD+1TZaZRRH+sFj3g+zRYsFoILkUSiSt9SBLy8c XPg9S3CGgBgzKDjOsQhdnEYSWGRx2JBc69d7Lxz7q/2b7bWKsSEPJ7LBsvIXM00skv63 PyceGp1GqJPg1HVMb1SI6T7rKGvCOnkd7EZxEpB8viC8dkF1ibaZFXRrolijgPJb6ftZ BnTNuKfccxPHdeVS71KG7Lwblu1ZbAi8M05v/EGgIFxhPqWHbDl3mCWrwRzhjMzLvkmO VK+mF6ruZe+bYQMT7lJr90T1lx2rkCQ9QH308W7iLrQI7VeJMxAqo35wel5oNhVBEyiH m71g== X-Gm-Message-State: ANhLgQ1dPzvYUBLOVCatF+6XumU2qolbHa/qXDA8dyHmq3kgYRhPC9VM j1TUa+w4mIEVoYfSoQ1ZCeAsvEZS X-Google-Smtp-Source: ADFU+vsC/FveQYc+d+swxVLz/N8PektcA9bqcq1kIMjsu4MAzXBW5HkJHAN4SgdRVROoL9SxwSRKDg== X-Received: by 2002:a63:f757:: with SMTP id f23mr3791644pgk.223.1583348173117; Wed, 04 Mar 2020 10:56:13 -0800 (PST) Received: from localhost.localdomain ([103.89.235.106]) by smtp.gmail.com with ESMTPSA id h12sm12720021pfk.124.2020.03.04.10.56.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Mar 2020 10:56:12 -0800 (PST) From: Leslie Monis To: netdev@vger.kernel.org Cc: davem@davemloft.net, tahiliani@nitk.edu.in, gautamramk@gmail.com Subject: [PATCH net-next v2 1/4] pie: use term backlog instead of qlen Date: Thu, 5 Mar 2020 00:25:59 +0530 Message-Id: <20200304185602.2540-2-lesliemonis@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200304185602.2540-1-lesliemonis@gmail.com> References: <20200304185602.2540-1-lesliemonis@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Remove ambiguity by using the term backlog instead of qlen when representing the queue length in bytes. Signed-off-by: Mohit P. Tahiliani Signed-off-by: Gautam Ramakrishnan Signed-off-by: Leslie Monis --- include/net/pie.h | 10 +++++----- net/sched/sch_pie.c | 22 +++++++++++----------- 2 files changed, 16 insertions(+), 16 deletions(-) diff --git a/include/net/pie.h b/include/net/pie.h index fd5a37cb7993..24f68c1e9919 100644 --- a/include/net/pie.h +++ b/include/net/pie.h @@ -46,7 +46,7 @@ struct pie_params { * @accu_prob: accumulated drop probability * @dq_count: number of bytes dequeued in a measurement cycle * @avg_dq_rate: calculated average dq rate - * @qlen_old: queue length during previous qdelay calculation + * @backlog_old: queue backlog during previous qdelay calculation * @accu_prob_overflows: number of times accu_prob overflows */ struct pie_vars { @@ -58,7 +58,7 @@ struct pie_vars { u64 accu_prob; u64 dq_count; u32 avg_dq_rate; - u32 qlen_old; + u32 backlog_old; u8 accu_prob_overflows; }; @@ -127,12 +127,12 @@ static inline void pie_set_enqueue_time(struct sk_buff *skb) } bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, - struct pie_vars *vars, u32 qlen, u32 packet_size); + struct pie_vars *vars, u32 backlog, u32 packet_size); void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, - struct pie_vars *vars, u32 qlen); + struct pie_vars *vars, u32 backlog); void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, - u32 qlen); + u32 backlog); #endif diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c index 915bcdb59a9f..8a2f9f11c86f 100644 --- a/net/sched/sch_pie.c +++ b/net/sched/sch_pie.c @@ -31,7 +31,7 @@ struct pie_sched_data { }; bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, - struct pie_vars *vars, u32 qlen, u32 packet_size) + struct pie_vars *vars, u32 backlog, u32 packet_size) { u64 rnd; u64 local_prob = vars->prob; @@ -51,7 +51,7 @@ bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, /* If we have fewer than 2 mtu-sized packets, disable pie_drop_early, * similar to min_th in RED */ - if (qlen < 2 * mtu) + if (backlog < 2 * mtu) return false; /* If bytemode is turned on, use packet size to compute new @@ -215,7 +215,7 @@ static int pie_change(struct Qdisc *sch, struct nlattr *opt, } void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, - struct pie_vars *vars, u32 qlen) + struct pie_vars *vars, u32 backlog) { psched_time_t now = psched_get_time(); u32 dtime = 0; @@ -231,7 +231,7 @@ void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, vars->dq_tstamp = now; - if (qlen == 0) + if (backlog == 0) vars->qdelay = 0; if (dtime == 0) @@ -244,7 +244,7 @@ void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, * we have enough packets to calculate the drain rate. Save * current time as dq_tstamp and start measurement cycle. */ - if (qlen >= QUEUE_THRESHOLD && vars->dq_count == DQCOUNT_INVALID) { + if (backlog >= QUEUE_THRESHOLD && vars->dq_count == DQCOUNT_INVALID) { vars->dq_tstamp = psched_get_time(); vars->dq_count = 0; } @@ -283,7 +283,7 @@ void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, * dq_count to 0 to re-enter the if block when the next * packet is dequeued */ - if (qlen < QUEUE_THRESHOLD) { + if (backlog < QUEUE_THRESHOLD) { vars->dq_count = DQCOUNT_INVALID; } else { vars->dq_count = 0; @@ -307,7 +307,7 @@ void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params, EXPORT_SYMBOL_GPL(pie_process_dequeue); void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, - u32 qlen) + u32 backlog) { psched_time_t qdelay = 0; /* in pschedtime */ psched_time_t qdelay_old = 0; /* in pschedtime */ @@ -322,7 +322,7 @@ void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, vars->qdelay_old = vars->qdelay; if (vars->avg_dq_rate > 0) - qdelay = (qlen << PIE_SCALE) / vars->avg_dq_rate; + qdelay = (backlog << PIE_SCALE) / vars->avg_dq_rate; else qdelay = 0; } else { @@ -330,10 +330,10 @@ void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, qdelay_old = vars->qdelay_old; } - /* If qdelay is zero and qlen is not, it means qlen is very small, + /* If qdelay is zero and backlog is not, it means backlog is very small, * so we do not update probabilty in this round. */ - if (qdelay == 0 && qlen != 0) + if (qdelay == 0 && backlog != 0) update_prob = false; /* In the algorithm, alpha and beta are between 0 and 2 with typical @@ -409,7 +409,7 @@ void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, vars->prob -= vars->prob / 64; vars->qdelay = qdelay; - vars->qlen_old = qlen; + vars->backlog_old = backlog; /* We restart the measurement cycle if the following conditions are met * 1. If the delay has been low for 2 consecutive Tupdate periods From patchwork Wed Mar 4 18:56:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leslie Monis X-Patchwork-Id: 1249182 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=m5MGSYwT; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48XjlR0S9nz9sP7 for ; Thu, 5 Mar 2020 05:56:19 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388300AbgCDS4S (ORCPT ); Wed, 4 Mar 2020 13:56:18 -0500 Received: from mail-pj1-f68.google.com ([209.85.216.68]:32989 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388219AbgCDS4R (ORCPT ); Wed, 4 Mar 2020 13:56:17 -0500 Received: by mail-pj1-f68.google.com with SMTP id o21so1293544pjs.0 for ; Wed, 04 Mar 2020 10:56:17 -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=QfVlUkRWx96jKVo5Y/zvgqtMfTE1JVSuMZ+/gn0c/VM=; b=m5MGSYwTyu6J9JMdS38fNe++fsrnHqGPVHWk1hBTmp8QJ7W6bkEZLBo6rVmiuVfO4y 8lf6bUU2lJPHAXTZqKqeE2ecRufQDBGSs3pSGccVImWcdddbX0mxp5pkqDN41AvFVpWf IyYUzirJH6VSbWIkmHSMJrRtzXKJU+g++6JzbO1K0Oa0BPGXZJ2BQu//xikxcDny6/fw +0L1P6+M5sbGdoGIEXWh8dRnm+VgXr8QXh2TUmtoU3TMsTOwceYUbFwip9YslXwhan5e pjK8WVZgmhP9T5F/RIUrJDDke5QXYCHMser9BTtgyJLNuGiHRTCYL8A4PJnZsPC5PT9r e6KA== 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=QfVlUkRWx96jKVo5Y/zvgqtMfTE1JVSuMZ+/gn0c/VM=; b=SFfOEGQXGMeiT5ady1Uk8NVUm7Dl5UsiO6Qurby2V6JJE3bxJiYtb4fz+wsXhzkToD oCXMNk/V8Y/0JJ/9kO2nmRtgY1AG0vK3eQIUDe/XNGmrJKAyCFL2+Bf6d6D+mnkAH9Hl HDjF46OGdfMzye/prllN7QjmewyGFP5V3em2ooYG2wgslLz6Ynnx4PGdgSrpaJ57O/ae Dbr3lBS5hvH6QXOByejiB5/3nA/yDMTjpDcbLx94DCcDTIpeT79B+OZY43qAoS+CMAkR Y57Cd23lGVWlULRkYmp/S74LbSxw9CluPzcLAl2TqBXz5JxG3+fgtfgIS8pKluevk0LL wxMQ== X-Gm-Message-State: ANhLgQ05BTsic2/RHi3pyk31wRzbvYspP2/wZzi53Dmw9z6AtKWSz/ja LnPmKjOLLqdADqb5axjnuGGW6rGM X-Google-Smtp-Source: ADFU+vta9zkIQyaoTzU5HPxnSkYTZJHd52u45XxXx9hz0Bu78O90qWj4Af7p2kR0m/MqRf1e47zM4A== X-Received: by 2002:a17:902:b089:: with SMTP id p9mr4195737plr.85.1583348176455; Wed, 04 Mar 2020 10:56:16 -0800 (PST) Received: from localhost.localdomain ([103.89.235.106]) by smtp.gmail.com with ESMTPSA id h12sm12720021pfk.124.2020.03.04.10.56.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Mar 2020 10:56:15 -0800 (PST) From: Leslie Monis To: netdev@vger.kernel.org Cc: davem@davemloft.net, tahiliani@nitk.edu.in, gautamramk@gmail.com Subject: [PATCH net-next v2 2/4] pie: remove unnecessary type casting Date: Thu, 5 Mar 2020 00:26:00 +0530 Message-Id: <20200304185602.2540-3-lesliemonis@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200304185602.2540-1-lesliemonis@gmail.com> References: <20200304185602.2540-1-lesliemonis@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In function pie_calculate_probability(), the variables alpha and beta are of type u64. The variables qdelay, qdelay_old and params->target are of type psched_time_t (which is also u64). The explicit type casting done when calculating the value for the variable delta is redundant and not required. Signed-off-by: Mohit P. Tahiliani Signed-off-by: Gautam Ramakrishnan Signed-off-by: Leslie Monis --- net/sched/sch_pie.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c index 8a2f9f11c86f..198cfa34a00a 100644 --- a/net/sched/sch_pie.c +++ b/net/sched/sch_pie.c @@ -363,8 +363,8 @@ void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars, } /* alpha and beta should be between 0 and 32, in multiples of 1/16 */ - delta += alpha * (u64)(qdelay - params->target); - delta += beta * (u64)(qdelay - qdelay_old); + delta += alpha * (qdelay - params->target); + delta += beta * (qdelay - qdelay_old); oldprob = vars->prob; From patchwork Wed Mar 4 18:56:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leslie Monis X-Patchwork-Id: 1249183 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=lkF0Vj4N; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48XjlV4RyHz9sP7 for ; Thu, 5 Mar 2020 05:56:22 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388304AbgCDS4V (ORCPT ); Wed, 4 Mar 2020 13:56:21 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:34223 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388226AbgCDS4V (ORCPT ); Wed, 4 Mar 2020 13:56:21 -0500 Received: by mail-pl1-f194.google.com with SMTP id j7so1430727plt.1 for ; Wed, 04 Mar 2020 10:56:20 -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=Y8wxH2nA14A7hv8o/g+zRpjVLB3YpsPt7xyiLMGkmyo=; b=lkF0Vj4Ng0+R+w93S40KtnHzuC13VZFXVHt3Hb3BcEo7dLXr6Z1eJBIKwZvC3scq8R pRqJ7YN7C/AbAhSYnL0/omOL8PrVbrqOZH6N+Wa/U+FfoEUTi59UOFmDPaUdLhBodf25 PWGDeBfczRU3+FCp9y3tv/HwjLFdk1hWsAbn/hoaqS/mu/9BlIYxuoSRg6UN4diDMRW7 ZDalfo3XOoBoJRjWXxmKWsCmb5GJ7Hj9CDsErMt8ZaTan/dC0VWo5XwfaVgcJQctKb3q ZvIrHX63XPi4WO2lsqFzMKIMzvm/hmB1Wri5Gk1lbP5OUK9cBn3YAFB2Uw/hiR2jPlv8 JARA== 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=Y8wxH2nA14A7hv8o/g+zRpjVLB3YpsPt7xyiLMGkmyo=; b=fQrvbR0r5nbSOYWlb3jiTpsNneaVvrbA3hE7TW/EJ2L6+kKIJTzTVB9c8Nia1ylsxC DsZ9w5Dq8B4Yz4e6ONVK7AfSLnbgcmeVwpt9vBhNOHQ+A0rTBZddIpSL657HuiLbSm7c PSb5a2TR4rnBMyi6KdTkGBxJsHzxWUJEDHsZr+SSRT9HJstpZvbdUjpgSB3LL7rK3Fq3 FIijQZvEBIg1ZTBgwTeDQJfDnsccOSvna7ZGTLZeenVc7uuxNFs7z8lx1WIta2T6hsX+ Kbzbe0vB7SsLzCFxXefoxuAPbg3Czlyp/fUw6M3o3toQcgI5KDjqjxGG6NaivCXfFgmk slNA== X-Gm-Message-State: ANhLgQ1l6ub5122gU+t+d5PG9d3nPBUXoJmcfSr4W+yRCQlgTipXJwwZ epb4g7AadteT2qrQSA1vRARy7nVz X-Google-Smtp-Source: ADFU+vsALTAOTQ6Y2nWin+WMu9bpgI1uyVLTynDV3Nl4tfS0LW+a8JOK4CoYYui/msFKnnwwaiwtgw== X-Received: by 2002:a17:90a:ae0a:: with SMTP id t10mr4504093pjq.2.1583348179844; Wed, 04 Mar 2020 10:56:19 -0800 (PST) Received: from localhost.localdomain ([103.89.235.106]) by smtp.gmail.com with ESMTPSA id h12sm12720021pfk.124.2020.03.04.10.56.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Mar 2020 10:56:19 -0800 (PST) From: Leslie Monis To: netdev@vger.kernel.org Cc: davem@davemloft.net, tahiliani@nitk.edu.in, gautamramk@gmail.com Subject: [PATCH net-next v2 3/4] pie: remove pie_vars->accu_prob_overflows Date: Thu, 5 Mar 2020 00:26:01 +0530 Message-Id: <20200304185602.2540-4-lesliemonis@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200304185602.2540-1-lesliemonis@gmail.com> References: <20200304185602.2540-1-lesliemonis@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The variable pie_vars->accu_prob is used as an accumulator for probability values. Since probabilty values are scaled using the MAX_PROB macro denoting (2^64 - 1), pie_vars->accu_prob is likely to overflow as it is of type u64. The variable pie_vars->accu_prob_overflows counts the number of times the variable pie_vars->accu_prob overflows. The MAX_PROB macro needs to be equal to at least (2^39 - 1) in order to do precise calculations without any underflow. Thus MAX_PROB can be reduced to (2^56 - 1) without affecting the precision in calculations drastically. Doing so will eliminate the need for the variable pie_vars->accu_prob_overflows as the variable pie_vars->accu_prob will never overflow. Removing the variable pie_vars->accu_prob_overflows also reduces the size of the structure pie_vars to exactly 64 bytes. Signed-off-by: Mohit P. Tahiliani Signed-off-by: Gautam Ramakrishnan Signed-off-by: Leslie Monis --- include/net/pie.h | 5 +---- net/sched/sch_fq_pie.c | 1 - net/sched/sch_pie.c | 21 ++++++--------------- 3 files changed, 7 insertions(+), 20 deletions(-) diff --git a/include/net/pie.h b/include/net/pie.h index 24f68c1e9919..1c645b76a2ed 100644 --- a/include/net/pie.h +++ b/include/net/pie.h @@ -8,7 +8,7 @@ #include #include -#define MAX_PROB U64_MAX +#define MAX_PROB (U64_MAX >> BITS_PER_BYTE) #define DTIME_INVALID U64_MAX #define QUEUE_THRESHOLD 16384 #define DQCOUNT_INVALID -1 @@ -47,7 +47,6 @@ struct pie_params { * @dq_count: number of bytes dequeued in a measurement cycle * @avg_dq_rate: calculated average dq rate * @backlog_old: queue backlog during previous qdelay calculation - * @accu_prob_overflows: number of times accu_prob overflows */ struct pie_vars { psched_time_t qdelay; @@ -59,7 +58,6 @@ struct pie_vars { u64 dq_count; u32 avg_dq_rate; u32 backlog_old; - u8 accu_prob_overflows; }; /** @@ -107,7 +105,6 @@ static inline void pie_vars_init(struct pie_vars *vars) vars->accu_prob = 0; vars->dq_count = DQCOUNT_INVALID; vars->avg_dq_rate = 0; - vars->accu_prob_overflows = 0; } static inline struct pie_skb_cb *get_pie_cb(const struct sk_buff *skb) diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c index 214657eb3dfd..a9da8776bf5b 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -189,7 +189,6 @@ static int fq_pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, out: q->stats.dropped++; sel_flow->vars.accu_prob = 0; - sel_flow->vars.accu_prob_overflows = 0; __qdisc_drop(skb, to_free); qdisc_qstats_drop(sch); return NET_XMIT_CN; diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c index 198cfa34a00a..f52442d39bf5 100644 --- a/net/sched/sch_pie.c +++ b/net/sched/sch_pie.c @@ -62,27 +62,19 @@ bool pie_drop_early(struct Qdisc *sch, struct pie_params *params, else local_prob = vars->prob; - if (local_prob == 0) { + if (local_prob == 0) vars->accu_prob = 0; - vars->accu_prob_overflows = 0; - } - - if (local_prob > MAX_PROB - vars->accu_prob) - vars->accu_prob_overflows++; - - vars->accu_prob += local_prob; + else + vars->accu_prob += local_prob; - if (vars->accu_prob_overflows == 0 && - vars->accu_prob < (MAX_PROB / 100) * 85) + if (vars->accu_prob < (MAX_PROB / 100) * 85) return false; - if (vars->accu_prob_overflows == 8 && - vars->accu_prob >= MAX_PROB / 2) + if (vars->accu_prob >= (MAX_PROB / 2) * 17) return true; prandom_bytes(&rnd, 8); - if (rnd < local_prob) { + if ((rnd >> BITS_PER_BYTE) < local_prob) { vars->accu_prob = 0; - vars->accu_prob_overflows = 0; return true; } @@ -129,7 +121,6 @@ static int pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, out: q->stats.dropped++; q->vars.accu_prob = 0; - q->vars.accu_prob_overflows = 0; return qdisc_drop(skb, sch, to_free); } From patchwork Wed Mar 4 18:56:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leslie Monis X-Patchwork-Id: 1249184 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; 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Wed, 04 Mar 2020 10:56:23 -0800 (PST) Received: from localhost.localdomain ([103.89.235.106]) by smtp.gmail.com with ESMTPSA id h12sm12720021pfk.124.2020.03.04.10.56.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Mar 2020 10:56:22 -0800 (PST) From: Leslie Monis To: netdev@vger.kernel.org Cc: davem@davemloft.net, tahiliani@nitk.edu.in, gautamramk@gmail.com Subject: [PATCH net-next v2 4/4] pie: realign comment Date: Thu, 5 Mar 2020 00:26:02 +0530 Message-Id: <20200304185602.2540-5-lesliemonis@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200304185602.2540-1-lesliemonis@gmail.com> References: <20200304185602.2540-1-lesliemonis@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Realign a comment after the change introduced by the previous patch. Signed-off-by: Leslie Monis --- include/net/pie.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/include/net/pie.h b/include/net/pie.h index 1c645b76a2ed..3fe2361e03b4 100644 --- a/include/net/pie.h +++ b/include/net/pie.h @@ -38,15 +38,15 @@ struct pie_params { /** * struct pie_vars - contains pie variables - * @qdelay: current queue delay - * @qdelay_old: queue delay in previous qdelay calculation - * @burst_time: burst time allowance - * @dq_tstamp: timestamp at which dq rate was last calculated - * @prob: drop probability - * @accu_prob: accumulated drop probability - * @dq_count: number of bytes dequeued in a measurement cycle - * @avg_dq_rate: calculated average dq rate - * @backlog_old: queue backlog during previous qdelay calculation + * @qdelay: current queue delay + * @qdelay_old: queue delay in previous qdelay calculation + * @burst_time: burst time allowance + * @dq_tstamp: timestamp at which dq rate was last calculated + * @prob: drop probability + * @accu_prob: accumulated drop probability + * @dq_count: number of bytes dequeued in a measurement cycle + * @avg_dq_rate: calculated average dq rate + * @backlog_old: queue backlog during previous qdelay calculation */ struct pie_vars { psched_time_t qdelay;