Re: [RFC/PATCH, 2/4] readX_check() performance evaluation II

From: Andi Kleen
Date: Wed Jan 28 2004 - 15:28:41 EST


On Wed, 28 Jan 2004 21:15:54 +0100
Andi Kleen <ak@xxxxxxx> wrote:

>
> >
> > Just set a flag aka "may need checking", and let the check be done by the
> > actual "read_pcix_error()" code.
>
> Where would you put the flag?
>
> Doing it global may give false errors for the wrong device with async MCEs
> and on SMP.
>
> For putting it into the pci_dev you need to take logs to walk the list.
> If you delay it to a softirq for safely getting the lock it would be set too late.
>
> Putting it into a different table indexed by pci index would be also racy
> with hotplug.

... to follow up myself ...

I suppose moving the pci_dev lists to RCU could make the flag in pci-dev work. But it would be still
a bit tricky with preemptive kernels.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/