Messages in this thread | | | Date | Fri, 14 Feb 2003 16:44:36 -0300 | From | Werner Almesberger <> | Subject | Re: Kexec, DMA, and SMP |
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Zwane Mwaikambo wrote: > I don't think suspending devices is safe at that stage since removing > devices and walking lists and freeing memory and disabling devices and... > kicks up quite a storm.
If you *really* don't want to stop devices, you can use the "reserved, non-DMA memory" approach, kexec the kernel that records the crash dump, and then do a system-wide reset, or such.
But if you don't have that - possibly considerable - amount of memory to spare, you don't have much of a choice than to stop devices. Of course, crash dumps don't need a neat and clean shutdown, so you can avoid all the kfrees, and such.
(So adding a special mode to the power management code may be too much overhead. Besides, sometimes, you can just pull a reset line, and don't have to do anything even remotely related to power management.)
Also, for each device you're using when dumping, you should have some means to bring it into a defined state already.
- Werner
-- _________________________________________________________________________ / Werner Almesberger, Buenos Aires, Argentina wa@almesberger.net / /_http://www.almesberger.net/____________________________________________/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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