From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 066ACC04EB8 for ; Tue, 4 Dec 2018 06:51:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ABA6C2087F for ; Tue, 4 Dec 2018 06:51:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="q9Qsl5Gn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ABA6C2087F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726073AbeLDGvN (ORCPT ); Tue, 4 Dec 2018 01:51:13 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:37146 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725976AbeLDGvM (ORCPT ); Tue, 4 Dec 2018 01:51:12 -0500 Received: by mail-pl1-f195.google.com with SMTP id b5so7812427plr.4; Mon, 03 Dec 2018 22:51:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=m2bgCmm9oFGj+7a89CfW8WSKtMSZZzQPl2BTKevlZ38=; b=q9Qsl5GnjoKUDVPyQaDHIA0w7cY1yp0ZDagwuXQoGmJSSSQ9siAihfvZ5bT46t00BY OFtToLcKufzyMhdbBUI0c0moFJNdu4z7SGJqoosQ8wpQRDxumqF0sbI/UrIRJ5v65+NP l3vILYYt69168FoC9w9klBKs+d4Qrg0h5YfZgIKxwm1QozFIk6k5ytfY6zk2czUpLh49 EFj3vHw7tzVBg37S4Fth03rwCvGKbRwkJ1O7iveAGCIo2fFbX6Tvl8ac65FhsrPEwErX nuqpLNcdeFtR93QtyYRlkKQfjxPU23q5eP4dXKyXObYzrWTxuCHWfwnCT5wIQU8hBBVK +vtQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=m2bgCmm9oFGj+7a89CfW8WSKtMSZZzQPl2BTKevlZ38=; b=B8Rb6xllyXlRNBWLRJl8E0S3jns774tHoInRH/NyTCrVZ2yCZR5UeUw6IbHKMwwzCM fr1+dxMbISHTkYIADriV3Gj+CH7V0+ScC6Du1XvMwLLd21uZVIDSsc8EYAqMCJKlF3mD Gbw1MOpHidf88k92/2a7zZYZgVq6LEGtg8+NdGtWvw2waRDotflh7aFDAJvT+tSiHlmW d41S6qxud5FiS2Ee5/atDptRqwUorbM4eqF5VKDnM8eYC24lE5z0XtPNAOybEN0bPsHL JptzJ7S9Lsb/23h1zF1HG5Ey/eBaiPkMeKCg9S1/6+qFghRjqPvz3W/ZrE2Njdr7fO5a ck0w== X-Gm-Message-State: AA+aEWbrTdlC8yxQn80PtrqwBbwFeuoh4Xd1ST3/RPArEQjLdvTvb7Hc T+91dMjQGybj9liMgZHM30nSFwo3 X-Google-Smtp-Source: AFSGD/V5P4x2zNuuorNpTPc2KCkSOwwHsIZbnaXtvXOJgtek5ntT9s4VzTfELikXfh4OAXAFuCbVgA== X-Received: by 2002:a17:902:6ac5:: with SMTP id i5mr19095570plt.134.1543906272109; Mon, 03 Dec 2018 22:51:12 -0800 (PST) Received: from leo.usersys.redhat.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id 7sm63236968pfm.8.2018.12.03.22.51.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 03 Dec 2018 22:51:11 -0800 (PST) Date: Tue, 4 Dec 2018 14:51:01 +0800 From: Hangbin Liu To: Sukumar Gopalakrishnan Cc: davem@davemloft.net, karn@ka9q.net, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: hard-coded limit on unresolved multicast route cache in ipv4/ipmr.c causes slow, unreliable creation of multicast routes on busy networks Message-ID: <20181204065100.GT24677@leo.usersys.redhat.com> References: <147f730b-8cbf-b76d-f693-b3fdaf72a89c@ka9q.net> <20180721.220309.1193443933653884021.davem@davemloft.net> <20181120092321.GR24677@leo.usersys.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 26, 2018 at 10:44:49AM +0530, Sukumar Gopalakrishnan wrote: > Hi, > >  There is a patch to make this queue len configurable. Is below mentioned going > to be applied ? > > http://lkml.iu.edu/hypermail/linux/kernel/1810.3/02344.html It looks this topic stuckd again.. > > Regards, > Sukumar > > On Tue, Nov 20, 2018 at 2:55 PM Hangbin Liu wrote: > > Hi David, > > On Sat, Jul 21, 2018 at 10:03:09PM -0700, David Miller wrote: > > Yeah that limit is bogus for several reasons. > ... > > > > Therefore, it probably is safe and correct to remove this > > cache_resolve_queue_len altogether. > > > > Something like this: > > > > diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h > > index d633f737b3c6..b166465d7c05 100644 > > --- a/include/linux/mroute_base.h > > +++ b/include/linux/mroute_base.h > > @@ -234,7 +234,6 @@ struct mr_table_ops { > >   * @mfc_hash: Hash table of all resolved routes for easy lookup > >   * @mfc_cache_list: list of resovled routes for possible traversal > >   * @maxvif: Identifier of highest value vif currently in use > > - * @cache_resolve_queue_len: current size of unresolved queue > >   * @mroute_do_assert: Whether to inform userspace on wrong ingress > >   * @mroute_do_pim: Whether to receive IGMP PIMv1 > >   * @mroute_reg_vif_num: PIM-device vif index > > @@ -251,7 +250,6 @@ struct mr_table { > >       struct rhltable         mfc_hash; > >       struct list_head        mfc_cache_list; > >       int                     maxvif; > > -     atomic_t                cache_resolve_queue_len; > >       bool                    mroute_do_assert; > >       bool                    mroute_do_pim; > >       int                     mroute_reg_vif_num; > > diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c > > index 9f79b9803a16..c007cf9bfe82 100644 > > --- a/net/ipv4/ipmr.c > > +++ b/net/ipv4/ipmr.c > > @@ -747,8 +747,6 @@ static void ipmr_destroy_unres(struct mr_table *mrt, > struct mfc_cache *c) > >       struct sk_buff *skb; > >       struct nlmsgerr *e; > >  > > -     atomic_dec(&mrt->cache_resolve_queue_len); > > - > >       while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) { > >               if (ip_hdr(skb)->version == 0) { > >                       struct nlmsghdr *nlh = skb_pull(skb, > > @@ -1135,9 +1133,11 @@ static int ipmr_cache_unresolved(struct mr_table > *mrt, vifi_t vifi, > >       } > >  > >       if (!found) { > > +             bool was_empty; > > + > >               /* Create a new entry if allowable */ > > -             if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 || > > -                 (c = ipmr_cache_alloc_unres()) == NULL) { > > +             c = ipmr_cache_alloc_unres(); > > +             if (!c) { > >                       spin_unlock_bh(&mfc_unres_lock); > >  > >                       kfree_skb(skb); > > @@ -1163,11 +1163,11 @@ static int ipmr_cache_unresolved(struct mr_table > *mrt, vifi_t vifi, > >                       return err; > >               } > >  > > -             atomic_inc(&mrt->cache_resolve_queue_len); > > +             was_empty = list_empty(&mrt->mfc_unres_queue); > >               list_add(&c->_c.list, &mrt->mfc_unres_queue); > >               mroute_netlink_event(mrt, c, RTM_NEWROUTE); > >  > > -             if (atomic_read(&mrt->cache_resolve_queue_len) == 1) > > +             if (was_empty) > >                       mod_timer(&mrt->ipmr_expire_timer, > >                                 c->_c.mfc_un.unres.expires); > > In ipmr_expire_process() and ipmr_do_expire_process(), they start mod_timer > when !list_empty(&mrt->mfc_unres_queue), should here also be !was_empty? > > BTW, do you have any plan to apply this patch in kernel? > > Regards > Hangbin > > >       } > > @@ -1274,7 +1274,6 @@ static int ipmr_mfc_add(struct net *net, struct > mr_table *mrt, > >               if (uc->mfc_origin == c->mfc_origin && > >                   uc->mfc_mcastgrp == c->mfc_mcastgrp) { > >                       list_del(&_uc->list); > > -                     atomic_dec(&mrt->cache_resolve_queue_len); > >                       found = true; > >                       break; > >               } > > @@ -1322,7 +1321,7 @@ static void mroute_clean_tables(struct mr_table > *mrt, bool all) > >               mr_cache_put(c); > >       } > >  > > -     if (atomic_read(&mrt->cache_resolve_queue_len) != 0) { > > +     if (!list_empty(&mrt->mfc_unres_queue)) { > >               spin_lock_bh(&mfc_unres_lock); > >               list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, > list) { > >                       list_del(&c->list); > > @@ -2648,9 +2647,19 @@ static int ipmr_rtm_route(struct sk_buff *skb, > struct nlmsghdr *nlh, > >               return ipmr_mfc_delete(tbl, &mfcc, parent); > >  } > >  > > +static int queue_count(struct mr_table *mrt) > > +{ > > +     struct list_head *pos; > > +     int count = 0; > > +      > > +     list_for_each(pos, &mrt->mfc_unres_queue) > > +             count++; > > +     return count; > > +} > > + > >  static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb) > >  { > > -     u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len); > > +     u32 queue_len = queue_count(mrt); > >  > >       if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) || > >           nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) || > > diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c > > index 0d0f0053bb11..75e9c5a3e7ea 100644 > > --- a/net/ipv6/ip6mr.c > > +++ b/net/ipv6/ip6mr.c > > @@ -759,8 +759,6 @@ static void ip6mr_destroy_unres(struct mr_table *mrt, > struct mfc6_cache *c) > >       struct net *net = read_pnet(&mrt->net); > >       struct sk_buff *skb; > >  > > -     atomic_dec(&mrt->cache_resolve_queue_len); > > - > >       while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved)) != NULL) > { > >               if (ipv6_hdr(skb)->version == 0) { > >                       struct nlmsghdr *nlh = skb_pull(skb, > > @@ -1139,8 +1137,8 @@ static int ip6mr_cache_unresolved(struct mr_table > *mrt, mifi_t mifi, > >                *      Create a new entry if allowable > >                */ > >  > > -             if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 || > > -                 (c = ip6mr_cache_alloc_unres()) == NULL) { > > +             c = ip6mr_cache_alloc_unres(); > > +             if (!c) { > >                       spin_unlock_bh(&mfc_unres_lock); > >  > >                       kfree_skb(skb); > > @@ -1167,7 +1165,6 @@ static int ip6mr_cache_unresolved(struct mr_table > *mrt, mifi_t mifi, > >                       return err; > >               } > >  > > -             atomic_inc(&mrt->cache_resolve_queue_len); > >               list_add(&c->_c.list, &mrt->mfc_unres_queue); > >               mr6_netlink_event(mrt, c, RTM_NEWROUTE); > >  > > @@ -1455,7 +1452,6 @@ static int ip6mr_mfc_add(struct net *net, struct > mr_table *mrt, > >               if (ipv6_addr_equal(&uc->mf6c_origin, &c->mf6c_origin) && > >                   ipv6_addr_equal(&uc->mf6c_mcastgrp, &c->mf6c_mcastgrp)) > { > >                       list_del(&_uc->list); > > -                     atomic_dec(&mrt->cache_resolve_queue_len); > >                       found = true; > >                       break; > >               } > > @@ -1502,7 +1498,7 @@ static void mroute_clean_tables(struct mr_table > *mrt, bool all) > >               mr_cache_put(c); > >       } > >  > > -     if (atomic_read(&mrt->cache_resolve_queue_len) != 0) { > > +     if (!list_empty(&mrt->mfc_unres_queue)) { > >               spin_lock_bh(&mfc_unres_lock); > >               list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, > list) { > >                       list_del(&c->list); >