netdev - Re: [Xen-devel] Re: [PATCH] xen network backend driver

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: <20110119192823.GN2754@reaktio.net>
Date:	Wed, 19 Jan 2011 21:28:23 +0200
From:	Pasi Kärkkäinen <pasik@....fi>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
Cc:	Ben Hutchings <bhutchings@...arflare.com>,
	Ian Campbell <Ian.Campbell@...citrix.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	xen-devel <xen-devel@...ts.xensource.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Subject: Re: [Xen-devel] Re: [PATCH] xen network backend driver

On Wed, Jan 19, 2011 at 11:16:59AM -0800, Jeremy Fitzhardinge wrote:
> On 01/19/2011 10:05 AM, Ben Hutchings wrote:
> > Not in itself.  NAPI polling will run on the same CPU which scheduled it
> > (so wherever the IRQ was initially handled).  If the protocol used
> > between netfront and netback doesn't support RSS then RPS
> > <http://lwn.net/Articles/362339/> can be used to spread the RX work
> > across CPUs.
> 
> There's only one irq per netback which is bound to one (V)CPU at a
> time.  I guess we could extend it to have multiple irqs per netback and
> some way of distributing packet flows over them, but that would only
> really make sense if there's a single interface with much more traffic
> than the others; otherwise the interrupts should be fairly well
> distributed (assuming that the different netback irqs are routed to
> different cpus).
> 

Does "multiqueue" only work for NIC drivers (and frontend drivers),
or could it be used also for netback?

(afaik Linux multiqueue enables setting up multiple receive queues each having a separate irq.)

-- Pasi

--
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