From patchwork Tue Mar 14 03:05:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Xing X-Patchwork-Id: 13173593 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57469C6FD1F for ; Tue, 14 Mar 2023 03:06:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230111AbjCNDGh (ORCPT ); Mon, 13 Mar 2023 23:06:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230110AbjCNDGX (ORCPT ); Mon, 13 Mar 2023 23:06:23 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A34C7BA06; Mon, 13 Mar 2023 20:06:10 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id k18-20020a17090a591200b0023d36e30cb5so896973pji.1; Mon, 13 Mar 2023 20:06:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678763170; 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=2Glcb7gbJW/2Kbapciwm0FRpblb1W2IM9lseG0c3UVk=; b=P+3u6NYEU+wMUxXhli0xb9agEpaA6rAdyhhqv7F8djnqrYstY9on7CGvzQP1zdoevf NWkMtZEbWX/TxXP3XQF1660nVQPDjimbAZJQgpfrypNnkAjnTGKUTtl3xIfD/cOyxpg7 xOwJKroR6D35gqb6VUH8uigc7+K6RzQTe8KxLzJVw0rw8xp7wBYfkZsUhc1wPtggRpy+ YM48WOGRAxeWlSvOvx8pdiLGEWQD3+071OTvPApuEApVHf0cB5FgbsKkOoIEw76WNjbf 6NhoFg/wEgav9IwJbAxSqb+stO6g5dkh1ABPjrK2YbjATAbpPFYPHQ6CN+P44sYz/PnO WaRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678763170; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=2Glcb7gbJW/2Kbapciwm0FRpblb1W2IM9lseG0c3UVk=; b=oejqAvzFRAm33/1a9a8rQn4WHYHXD6G18B9Clsl7xp8O/903/322J31m0YgUTW3H7D 6uCtgusPwWisVLTF3I+iI5cMXBdiE3fsUoWE2NTRlVSi/Pefwj8sUkTFku6d27+RbHLv rt0vAmK0LH13VE3hX8fACNCwLkZrRktgTbjFOPZDgOB3tkcXcp/mqlQhx2/cfInxs5DR rfKflO7BVUaD+ThPHTBgn+V/7OMtJ0LCnzYWgpqxJEHW6pk4+W7b4gN3bLmNkIEkYkEJ eWWF/sTPMzs6hRKlA2K2Xbo7eaxloYsza1MIhZppruMgAOoyTU5BnzqHEmEyZPUjs78a y4iQ== X-Gm-Message-State: AO0yUKWecq4MgJFwC5FfsxxmByLKNYzSnQl9GGxCkcH5QczNMbXfOaTK DwqVOMsOWtVhKhPlhN5PCXk= X-Google-Smtp-Source: AK7set/796TeIZnCBEwRRYvVZikm6y42P68Ad5BNCAQW237yqA+PSSF65nn/QkHBVy16xpF9e3geaA== X-Received: by 2002:a05:6a20:6009:b0:d4:b24b:4459 with SMTP id r9-20020a056a20600900b000d4b24b4459mr3749090pza.13.1678763170003; Mon, 13 Mar 2023 20:06:10 -0700 (PDT) Received: from KERNELXING-MB0.tencent.com ([103.7.29.31]) by smtp.gmail.com with ESMTPSA id i17-20020aa787d1000000b005897f5436c0sm395433pfo.118.2023.03.13.20.06.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Mar 2023 20:06:09 -0700 (PDT) From: Jason Xing To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, stephen@networkplumber.org, simon.horman@corigine.com, sinquersw@gmail.com Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kerneljasonxing@gmail.com, Jason Xing Subject: [PATCH v2 net-next 2/2] net: introduce budget_squeeze to help us tune rx behavior Date: Tue, 14 Mar 2023 11:05:32 +0800 Message-Id: <20230314030532.9238-3-kerneljasonxing@gmail.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20230314030532.9238-1-kerneljasonxing@gmail.com> References: <20230314030532.9238-1-kerneljasonxing@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Jason Xing When we encounter some performance issue and then get lost on how to tune the budget limit and time limit in net_rx_action() function, we can separately counting both of them to avoid the confusion. Signed-off-by: Jason Xing Reviewed-by: Simon Horman --- v2: 1) change the coding style suggested by Stephen and Simon 2) Keep the display of the old data (time_squeeze) untouched suggested by Kui-Feng Link: https://lore.kernel.org/lkml/20230311163614.92296-1-kerneljasonxing@gmail.com/ --- include/linux/netdevice.h | 1 + net/core/dev.c | 12 ++++++++---- net/core/net-procfs.c | 9 ++++++--- 3 files changed, 15 insertions(+), 7 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 6a14b7b11766..5736311a2133 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3157,6 +3157,7 @@ struct softnet_data { /* stats */ unsigned int processed; unsigned int time_squeeze; + unsigned int budget_squeeze; #ifdef CONFIG_RPS struct softnet_data *rps_ipi_list; #endif diff --git a/net/core/dev.c b/net/core/dev.c index 253584777101..1518a366783b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6637,6 +6637,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) unsigned long time_limit = jiffies + usecs_to_jiffies(READ_ONCE(netdev_budget_usecs)); int budget = READ_ONCE(netdev_budget); + bool done = false; LIST_HEAD(list); LIST_HEAD(repoll); @@ -6644,7 +6645,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) list_splice_init(&sd->poll_list, &list); local_irq_enable(); - for (;;) { + while (!done) { struct napi_struct *n; skb_defer_free_flush(sd); @@ -6662,10 +6663,13 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) * Allow this to run for 2 jiffies since which will allow * an average latency of 1.5/HZ. */ - if (unlikely(budget <= 0 || - time_after_eq(jiffies, time_limit))) { + if (unlikely(budget <= 0)) { + sd->budget_squeeze++; + done = true; + } + if (unlikely(time_after_eq(jiffies, time_limit))) { sd->time_squeeze++; - break; + done = true; } } diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index 2809b663e78d..25810ee46a04 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -179,14 +179,17 @@ static int softnet_seq_show(struct seq_file *seq, void *v) */ seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x " - "%08x %08x\n", - sd->processed, sd->dropped, sd->time_squeeze, 0, + "%08x %08x %08x %08x\n", + sd->processed, sd->dropped, + sd->time_squeeze + sd->budget_squeeze, /* keep it untouched */ + 0, 0, 0, 0, 0, /* was fastroute */ 0, /* was cpu_collision */ sd->received_rps, flow_limit_count, softnet_backlog_len(sd), /* keep it untouched */ (int)seq->index, - softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd)); + softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd), + sd->time_squeeze, sd->budget_squeeze); return 0; }