From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] Rate should be u64 to avoid integer overflow at high speeds (>= ~35Gbit) Date: Sat, 09 Mar 2013 20:03:49 -0800 Message-ID: <1362888229.4051.2.camel@edumazet-glaptop> References: <1362885604-14006-1-git-send-email-j.vimal@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, shemminger@vyatta.com To: Vimalkumar Return-path: Received: from mail-ea0-f178.google.com ([209.85.215.178]:44188 "EHLO mail-ea0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751886Ab3CJEDx (ORCPT ); Sat, 9 Mar 2013 23:03:53 -0500 Received: by mail-ea0-f178.google.com with SMTP id g14so707102eak.23 for ; Sat, 09 Mar 2013 20:03:51 -0800 (PST) In-Reply-To: <1362885604-14006-1-git-send-email-j.vimal@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 2013-03-09 at 19:20 -0800, Vimalkumar wrote: > Since rate values are passed around between kernel and tc > in bytes/sec, 2**32 bytes/sec is around 34Gb/s. Beyond that > rate, htb, tbf, hfsc, etc. can never be configured correctly. > > Signed-off-by: Vimalkumar > --- > include/linux/gen_stats.h | 2 +- > include/linux/pkt_sched.h | 10 +++++----- > misc/ifstat.c | 4 ++-- > tc/m_police.c | 2 +- > tc/q_cbq.c | 2 +- > tc/q_choke.c | 2 +- > tc/q_gred.c | 2 +- > tc/q_hfsc.c | 6 ++++-- > tc/q_red.c | 2 +- > tc/tc_cbq.c | 4 ++-- > tc/tc_cbq.h | 4 ++-- > tc/tc_core.c | 4 ++-- > tc/tc_core.h | 4 ++-- > tc/tc_util.c | 6 +++--- > tc/tc_util.h | 6 +++--- > 15 files changed, 31 insertions(+), 29 deletions(-) > > diff --git a/include/linux/gen_stats.h b/include/linux/gen_stats.h > index 552c8a0..5ca6015 100644 > --- a/include/linux/gen_stats.h > +++ b/include/linux/gen_stats.h > @@ -33,7 +33,7 @@ struct gnet_stats_basic_packed { > * @pps: current packet rate > */ > struct gnet_stats_rate_est { > - __u32 bps; > + __u64 bps; > __u32 pps; > }; > > diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h > index 32aef0a..d6bc658 100644 > --- a/include/linux/pkt_sched.h > +++ b/include/linux/pkt_sched.h > @@ -35,7 +35,7 @@ struct tc_stats { > __u32 drops; /* Packets dropped because of lack of resources */ > __u32 overlimits; /* Number of throttle events when this > * flow goes out of allocated bandwidth */ > - __u32 bps; /* Current flow byte rate */ > + __u64 bps; /* Current flow byte rate */ > __u32 pps; /* Current flow packet rate */ > __u32 qlen; > __u32 backlog; > @@ -79,7 +79,7 @@ struct tc_ratespec { > unsigned short overhead; > short cell_align; > unsigned short mpu; > - __u32 rate; > + __u64 rate; > }; > You cannot do that without breaking user land tools. Not only tc, but all user applications as well. We need to support compatibility, before considering adding such changes.