Messages in this thread | | | Date | Tue, 28 Feb 2012 09:43:52 -0800 (PST) | From | Andrei Warkentin <> | Subject | Re: [PATCHv3 1/3] NETPOLL: Extend rx_hook support. |
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Hi,
----- Original Message ----- > From: "Jason Wessel" <jason.wessel@windriver.com> > To: "Andrei Warkentin" <awarkentin@vmware.com> > Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Andrei Warkentin" <andreiw@vmware.com>, > kgdb-bugreport@lists.sourceforge.net, "Matt Mackall" <mpm@selenic.com>, "Andrei Warkentin" > <andrey.warkentin@gmail.com> > Sent: Tuesday, February 28, 2012 11:06:44 AM > Subject: Re: [PATCHv3 1/3] NETPOLL: Extend rx_hook support. >
> > All that netpoll_poll() did was to call netpoll_poll_dev(). I have > not yet looked at the differences between kgdboe and the netkdb code > you proposed but I would have suspected it also falls victim to the > ethernet preemption problem which prevented kgdboe from ever being > considered for a mainline merge. Certainly there are ways to fix > this > problem but most involved changes to scheduling, core net code, or > substantial driver specific changes. >
I see, I read up on the issues w.r.t. preemption. Could this be worked around by modifiying affected drivers to bypass locking if they are used in KDB context? Make some accessor netdev-specific lock/unlocks that won't do anything if running in KDB context.
> > > > > This is slight OT, but...are WiFi drivers sufficiently similar that > > netpoll "just works?" > > Yes and no. Yes, you could use the NET_POLL api to transmit packets > if the driver implemented polling hooks, but no in the sense that > most > of the time you need a user space driver to manage the keys which are > time sensitive for things like WPA (usually the job of wpa > supplicant). This is going to prevent you from having WiFi work at > all while the kernel is in the critical exception state. >
Ah right. I was thinking just open networking. I should give that a try...
A
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