On Mon, Nov 04, 2002 at 04:40:11PM +0000, Alan Cox wrote:
> Let me ask another question here
>
> Other than "register_reboot_notifier()" and adding a
> "register_exception_notifier()" chain what else does a dump tool need.
> Register_exception_notifier seems to solve about 90% of the insmod gdb
> problem space as well ?
>
>
I had tried to list these in an earlier mail, added a few more
comments now marked by ">>"
1.Enabling IPI to collect CPU state on all processors in the
system right when dump is triggered (may not be a normal
situation, so NMIs where supported are the best option)
>> set/register_nmi_callback could also help in part (though
>> synchronization issues need to be thought through so that
>> the effect on regular system operation is as low as possible),
>> but we also need an interface to generate the NMI ipi when
>> required, and something that generalises on all architectures.
2.Ability to quiesce (silence) the system before dumping
(and if in non-disruptive mode, then restore it back)
>> smp_call_function may not the ideal option for many situations
>> - in general we would like to have a separate "force" path
>> available for some troublesome situations, and it would be
>> nice to be able to tackle non-disruptive (but accurate) dumping
>> as well.
>> maybe 1 & 2 can be combined in some form
>> Dump should preferably not overlap with a regularly used IPI.
3. Calls into dump from kernel paths (panic, oops, sysrq
etc).
>> This is where your register_xxx_notifier(s) fit in
4. Exports of symbols to help with physical memory
traversal and verification
>> Covers what Andi Kleen referred to as
>> iterate_over_memmap_and_give_me_type()
>> (a way to figure out the type of memory - true ram or other)
Regards
Suparna
-- Suparna Bhattacharya (suparna@in.ibm.com) Linux Technology Center IBM Software Labs, India- 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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