Date: Fri, 12 Sep 2014 10:09:44 +0200 From: =?ISO-8859-1?Q?Olivier_Cochard=2DLabb=E9?= <olivier@cochard.me> To: Bruce Evans <brde@optusnet.com.au> Cc: freebsd-net <freebsd-net@freebsd.org>, Ryan Stone <rysto32@gmail.com> Subject: Re: [PATCH] Fix integer truncation in systat -ifstat Message-ID: <CA%2Bq%2BTcpWLMrZHb_=fbgy_FdjCsSRzZcdBoOMQJB1BWdxKkSMHw@mail.gmail.com> In-Reply-To: <20140912154903.L923@besplex.bde.org> References: <CAFMmRNwk4dQx3ZP85RWFRYELoxFCxjE5oiCbkGgb-00QnO7xpw@mail.gmail.com> <20140912154903.L923@besplex.bde.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, Sep 12, 2014 at 8:41 AM, Bruce Evans <brde@optusnet.com.au> wrote: > Only differences in the counters are used except in 1 place that is > broken in other ways, so overflow is only a large problem starting at > about 40 Gbps. At only 10 Gbps, 32-bit counters are enough with a > refresh interval of 1 second but not quite enough with the default > interval of 5 seconds (this default is not documented in the man > page. It seems to only be documented (with a grammar error -- comma > splice) in the status message for mode switches). 5 seconds at > nearly 1.125 GBps exceeds UINT32_MAX. Packet counter overflow isn't > a problem until about 600 Gbps with the default interval. 32-bit > systems would have other problems supporting 600 GBps interfaces. > I confirm this behavior reported in this PR: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=182448
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CA%2Bq%2BTcpWLMrZHb_=fbgy_FdjCsSRzZcdBoOMQJB1BWdxKkSMHw>