netdev - Re: CLOCK_MONOTONIC datagram timestamps by the kernel

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 01 Mar 2007 07:54:44 -0800
From:	Stephen Hemminger <shemminger@...ux-foundation.org>
To:	Eric Dumazet <dada1@...mosbay.com>
CC:	John find <linux.kernel@...e.fr>, linux-net@...r.kernel.org,
	netdev@...r.kernel.org
Subject: Re: CLOCK_MONOTONIC datagram timestamps by the kernel

Eric Dumazet wrote:
> On Wednesday 28 February 2007 17:07, John wrote:
>
>   
>> Consider an idle Linux 2.6.20-rt8 system, equipped with a single PCI-E
>> gigabit Ethernet NIC, running on a modern CPU (e.g. Core 2 Duo E6700).
>> All this system does is time stamp 1000 packets per second.
>>
>> Are you claiming that this platform *cannot* handle most packets within
>> less than 1 microsecond of their arrival?
>>     
>
> Yes I claim it.
>
> You expect too much of this platform, unless "most" means 10 % for 
> you ;)
>
> If you replace "1 us" by "50 us", then yes, it probably can do it, if "most" 
> means 99%, (not 99.999 %)
>
> Anyway, if you want to play, you can apply this patch on top of 
> linux-2.6.21-rc2  (nanosecond resolution infrastruture needs 2.6.21)
> I let you do the adjustments for rt kernel.
>
>   
I like it except changing stamp to stampns all over the place is 
unnecessary, just change the
type.

> I compiled it on my i386 machine, and tested it with a patched libpcap/tcpdump
>
>   
I assume old tcpdump works as expected.
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html