netdev - Re: rps testing questions

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]

Message-ID: <1295269713.3700.5.camel@localhost>
Date:	Mon, 17 Jan 2011 13:08:33 +0000
From:	Ben Hutchings <bhutchings@...arflare.com>
To:	mi wake <wakemi.wake@...il.com>
Cc:	netdev@...r.kernel.org
Subject: Re: rps testing questions

On Mon, 2011-01-17 at 17:43 +0800, mi wake wrote:
> I do a rps(Receive Packet Steering) testing on centos 5.5 with  kernel 2.6.37.
> cpu: 8 core Intel.
> ethernet adapter: bnx2x
> 
> Problem statement:
> enable rps with:
> echo "ff" > /sys/class/net/eth2/queues/rx-0/rps_cpus.
> 
> running 1 instances of netperf TCP_RR: netperf  -t TCP_RR -H 192.168.0.1 -c -C
> without rps: 9963.48(Trans Rate per sec)
> with rps:  9387.59(Trans Rate per sec)
> 
> I do ab and tbench testing also find there is less tps with enable
> rps.but,there is more cpu using when with enable rps.when with enable
> rps ，softirqs is blanced  on cpus.
> 
> is there something wrong with my test？

In addition to what Eric said, check the interrupt moderation settings
(ethtool -c/-C options).  One-way latency for a single request/response
test will be at least the interrupt moderation value.

I haven't tested RPS by itself (Solarflare NICs have plenty of hardware
queues) so I don't know whether it can improve latency.  However, RFS
certainly does when there are many flows.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

--
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