Re: [patch 1/3] kdump: use is_kdump_kernel() in sba_init()

From: Simon Horman
Date: Tue Jul 29 2008 - 18:40:55 EST


On Tue, Jul 29, 2008 at 10:51:56AM -0400, Vivek Goyal wrote:
> On Tue, Jul 29, 2008 at 06:12:36PM +1000, Simon Horman wrote:
> > After recent patches* is_kdump_kernel() should return 1 in the
> > case where code is executing in a crashkernel and 0 otherwise.
> > It is save to use outside of CONFIG_KDUMP.
> >
> > * http://lkml.org/lkml/2008/7/28/445
> >
>
> Hi Simon,
>
> is_kdump_kernel() returns 1 when both the following conditions are true.
>
> - CONFIG_CRASH_DUMP is enabled
> - And kernel is booting after a panic.
>
> If any of the above condition is not true, it returns 0.
>
> So for the cases where, CONFIG_CRASH_DUMP=n and kernel is booting after
> panic, is_kdump_kernel() will still return 0.
>
> This essentially means that any kernel which is booting after a panic,
> but does not have CONFIG_CRASH_DUMP enabled, will not take special actions
> required for booting that kernel. Until, somebody can come up with another
> usage of booting a kernel after a panic (apart from crash dump), I think
> this is good enough an assumption.
>
> So your changes will work. I just wanted to clarify the semantics more
> explicitly.

Hi Vivek,

sorry if my explanation was confused. The scheme that you describe
above is what I am working with too.

--
Horms

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