netdev - Re: Drops in qdisc on ifb interface

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, 28 May 2015 09:26:46 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	John Fastabend <john.fastabend@...il.com>
Cc:	"jsullivan@...nsourcedevel.com" <jsullivan@...nsourcedevel.com>,
	netdev@...r.kernel.org
Subject: Re: Drops in qdisc on ifb interface

 On Thu, 2015-05-28 at 08:45 -0700, John Fastabend wrote:
> If your experimenting one thing you could do is create many
> ifb devices and load balance across them from tc. I'm not
> sure if this would be practical in your setup or not but might
> be worth trying.
> 
> One thing I've been debating adding is the ability to match
> on current cpu_id in tc which would allow you to load balance by
> cpu. I could send you a patch if you wanted to test it. I would
> expect this to help somewhat with 'single queue' issue but sorry
> haven't had time yet to test it out myself.

It seems John uses a single 1Gbps flow, so only one cpu would receive
NIC interrupts.

The only way he could get better results would be to schedule IFB work
on another core.

(Assuming one cpu is 100% busy servicing NIC + IFB, but I really doubt
it...)



--
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