netdev - Re: First pass at MSG_FASTOPEN support in top-of-trunk netperf

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] [day] [month] [year] [list]

Date:	Tue, 28 Aug 2012 10:10:30 -0700
From:	Rick Jones <rick.jones2@...com>
To:	"H.K. Jerry Chu" <hkjerry.chu@...il.com>
CC:	netdev@...r.kernel.org
Subject: Re: First pass at MSG_FASTOPEN support in top-of-trunk netperf

>> There was a ~25% increase in TCP_CRR performance, even without the server
>> actually accepting the magic TCP option.  Is that actually expected?
>
> I have a locally enhanced netperf for TCP_CRR over Fast Open and I've
>   noticed the numbers can change drastically between runs. I have not got
> the time to investigate why. (Does it have to do with scheduler and CPU
> locality?) How consistent is your perf number?

I recall the performance being reasonably consistent but there has been 
a vacation of my own in the middle there so my dimm memory is a bit fuzzy :)

Historically (and going beyond just Linux) a TCP_CRR test can have some 
non-trivial run to run variation thanks to (attempted) TIME_WAIT reuse. 
  Whether that is happening to you I don't know, but it might be worth a 
look.

> I plan to submit the server side code soon and will work with you to add
> the server side support to TCP_CRR (it requires a new TCP_FASTOPEN
> socket option to enable Fast Open on a listener.)

Works for me.

happy benchmarking,

rick jones
--
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