From patchwork Mon Aug 29 11:47:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Gobert X-Patchwork-Id: 12957704 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 34D70ECAAD2 for ; Mon, 29 Aug 2022 12:11:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230289AbiH2MLP (ORCPT ); Mon, 29 Aug 2022 08:11:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229513AbiH2MK4 (ORCPT ); Mon, 29 Aug 2022 08:10:56 -0400 Received: from mail-wm1-f42.google.com (mail-wm1-f42.google.com [209.85.128.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED2B02BE2; Mon, 29 Aug 2022 04:55:58 -0700 (PDT) Received: by mail-wm1-f42.google.com with SMTP id m17-20020a7bce11000000b003a5bedec07bso8044844wmc.0; Mon, 29 Aug 2022 04:55:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=user-agent:content-disposition:mime-version:message-id:subject:to :from:date:from:to:cc; bh=IRQQodgrI0rD6EnFTbfw2xeJ3D9VPk4cilZ4rKqcs2s=; b=I2gVmNfGRk97P073p11Fzfpoyc8jaV4344s+6x4KYyqkS6KxaPxEgqOgN9IBzfgs98 bpnrYyraIgjSQqwsyD0O/xQ4CkQiL31avQ172TXu1bkeWN+V6gAt3FVtALYDUD4Fc4dZ 0i6LYUdM/iNJArhk8oPo0VbLXrkLsL6SHiKvneLgmq00JGCmkM0+yLzmyXLUQ0+RRS5j 40GhMeoTcpaOc9A0wiCefIu1M3Sn9KCF8IEUDzoR8/hrcUbiW3d4U9hp5RGin/HHBEFb TFu8y7DwF0XIdB12y83MR758WPbQO31QN+z3jF+nLjUaGf38uK65ndmLr8MrG+k6mb0o VEOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent:content-disposition:mime-version:message-id:subject:to :from:date:x-gm-message-state:from:to:cc; bh=IRQQodgrI0rD6EnFTbfw2xeJ3D9VPk4cilZ4rKqcs2s=; b=Et85OrLTu1pmtbsjbMy2Gcrx5TO3brdkix/JRz2mVxXZG3S7pt50SLymA4Py98Ry3P ntXnAxCKC+VeJZ1ENOYIxfq0jVe+TQuWSBK9xkbuMH/ulqHUejZGTrJOJc/x8rePpsQ4 Re6k5m8pYM8q0jj/lPHlGkktrlG4O76Cvi021bU8XjObRCR0ctasm9oPvJvGDaf1vUPm nEJHKkDiR4k0DTFuiUCtY/EPreVBHOh5BIK8gdjdr96g91qo0MDSA2VWKna72U2pRD8x zYcb8uxsymYTfClPsGao00ozKVg5tpj1VbmSvjzuY2fz/3CSasCjHpLwbhvpoj/oVj6V BAkg== X-Gm-Message-State: ACgBeo3mqJQxMQw5YTMsJgyoRmcjn8n4dbtAQpq7tO89budd2W6voYIh FMKr1KxE/QIvugG7ajJ8nAM= X-Google-Smtp-Source: AA6agR5+TRvLKL/hosvHkbd9eCcEl4Wk9DuFLZLrpdGPTJ0t4wvGsTFJIwtXVuOLW+wjIaYxu+H/Mw== X-Received: by 2002:a05:600c:1c88:b0:3a8:3e79:7214 with SMTP id k8-20020a05600c1c8800b003a83e797214mr5101643wms.155.1661773782991; Mon, 29 Aug 2022 04:49:42 -0700 (PDT) Received: from debian ([89.238.191.199]) by smtp.gmail.com with ESMTPSA id r10-20020adff10a000000b002211fc70174sm7851027wro.99.2022.08.29.04.49.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Aug 2022 04:49:42 -0700 (PDT) Date: Mon, 29 Aug 2022 13:47:49 +0200 From: Richard Gobert To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, corbet@lwn.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, alex.aring@gmail.com, stefan@datenfreihafen.org, pablo@netfilter.org, kadlec@netfilter.org, fw@strlen.de, kafai@fb.com, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-wpan@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org Subject: [PATCH 4/4] net-next: frags: dynamic timeout under load Message-ID: <20220829114739.GA2436@debian> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-wpan@vger.kernel.org Calculate a dynamic fragment reassembly timeout, taking into consideration the current fqdir load and the load introduced by the peer. Reintroduce low_thresh, which now acts as a knob for adjusting per-peer memory limits. Signed-off-by: Richard Gobert --- Documentation/networking/ip-sysctl.rst | 3 +++ include/net/inet_frag.h | 1 + net/ipv4/inet_fragment.c | 30 +++++++++++++++++++++++++- net/ipv4/ip_fragment.c | 2 +- 4 files changed, 34 insertions(+), 2 deletions(-) diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index 56cd4ea059b2..fb25aa6e22a2 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -247,6 +247,9 @@ ipfrag_low_thresh - LONG INTEGER begins to remove incomplete fragment queues to free up resources. The kernel still accepts new fragments for defragmentation. + (Since linux-6.1) + Maximum memory used to reassemble IP fragments sent by a single peer. + ipfrag_time - INTEGER Time in seconds to keep an IP fragment in memory. diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h index 077a0ec78a58..595a6db57a0e 100644 --- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -99,6 +99,7 @@ struct inet_frag_queue { u16 max_size; struct fqdir *fqdir; struct inet_peer *peer; + u64 timeout; struct rcu_head rcu; }; diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index 8b8d77d548d4..34c5ebba4951 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -314,6 +314,30 @@ void inet_frag_free(struct inet_frag_queue *q) call_rcu(&q->rcu, inet_frag_destroy_rcu); } +static int inet_frag_update_timeout(struct inet_frag_queue *q) +{ + u64 peer_timeout, inet_timeout; + long peer_mem, inet_mem; + long high_thresh = READ_ONCE(q->fqdir->high_thresh); + long low_thresh = READ_ONCE(q->fqdir->low_thresh); + u64 base_timeout = READ_ONCE(q->fqdir->timeout); + + peer_mem = low_thresh - peer_mem_limit(q); + inet_mem = high_thresh - frag_mem_limit(q->fqdir); + + if (peer_mem <= 0 || inet_mem <= 0) + return -ENOMEM; + + /* Timeout changes linearly with respect to the amount of free memory. + * Choose the more permissive of the two timeouts, to avoid limiting + * the system while there is still enough memory. + */ + peer_timeout = div64_long(base_timeout * peer_mem, low_thresh); + inet_timeout = div64_long(base_timeout * inet_mem, high_thresh); + q->timeout = max_t(u64, peer_timeout, inet_timeout); + return 0; +} + void inet_frag_destroy(struct inet_frag_queue *q) { struct fqdir *fqdir; @@ -346,6 +370,10 @@ static struct inet_frag_queue *inet_frag_alloc(struct fqdir *fqdir, q->fqdir = fqdir; f->constructor(q, arg); + if (inet_frag_update_timeout(q)) { + inet_frag_free(q); + return NULL; + } add_frag_mem_limit(q, f->qsize); timer_setup(&q->timer, f->frag_expire, 0); @@ -367,7 +395,7 @@ static struct inet_frag_queue *inet_frag_create(struct fqdir *fqdir, *prev = ERR_PTR(-ENOMEM); return NULL; } - mod_timer(&q->timer, jiffies + fqdir->timeout); + mod_timer(&q->timer, jiffies + q->timeout); *prev = rhashtable_lookup_get_insert_key(&fqdir->rhashtable, &q->key, &q->node, f->rhash_params); diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index e35061f6aadb..88a99242d721 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -236,7 +236,7 @@ static int ip_frag_reinit(struct ipq *qp) { unsigned int sum_truesize = 0; - if (!mod_timer(&qp->q.timer, jiffies + qp->q.fqdir->timeout)) { + if (!mod_timer(&qp->q.timer, jiffies + qp->q.timeout)) { refcount_inc(&qp->q.refcnt); return -ETIMEDOUT; }