Messages in this thread | | | Date | Wed, 29 Oct 2014 20:50:54 +0100 | From | Peter Zijlstra <> | Subject | Re: e1000_netpoll(): disable_irq() triggers might_sleep() on linux-next |
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On Wed, Oct 29, 2014 at 08:49:03PM +0100, Thomas Gleixner wrote: > On Wed, 29 Oct 2014, Peter Zijlstra wrote: > > > On Wed, Oct 29, 2014 at 07:33:00PM +0100, Thomas Gleixner wrote: > > > Yuck. No. You are just papering over the problem. > > > > > > What happens if you add 'threadirqs' to the kernel command line? Or if > > > the interrupt line is shared with a real threaded interrupt user? > > > > > > The proper solution is to have a poll_lock for e1000 which serializes > > > the hardware interrupt against netpoll instead of using > > > disable/enable_irq(). > > > > > > In fact that's less expensive than the disable/enable_irq() dance and > > > the chance of contention is pretty low. If done right it will be a > > > NOOP for the CONFIG_NET_POLL_CONTROLLER=n case. > > > > > > > OK a little something like so then I suppose.. But I suspect most all > > the network drivers will need this and maybe more, disable_irq() is a > > popular little thing and we 'just' changed semantics on them. > > We changed that almost 4 years ago :) What we 'just' did was to add a > prominent warning into the code.
You know that is the same right... they didn't know it was broken therefore it wasn't :-), but now they need to go actually do stuff about it, an entirely different proposition.
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