Re: [PATCH RFC 3/6] kexec: export PG_offline to VMCOREINFO

From: Borislav Petkov
Date: Thu Nov 15 2018 - 06:10:40 EST


On Thu, Nov 15, 2018 at 02:19:23PM +0800, Dave Young wrote:
> It would be good to copy some background info from cover letter to the
> patch description so that we can get better understanding why this is
> needed now.
>
> BTW, Lianbo is working on a documentation of the vmcoreinfo exported
> fields. Ccing him so that he is aware of this.
>
> Also cc Boris, although I do not want the doc changes blocks this
> he might have different opinion :)

Yeah, my initial reaction is that exporting an mm-internal flag to
userspace is a no-no.

What would be better, IMHO, is having a general method of telling the
kdump kernel - maybe ranges of physical addresses - which to skip.

Because the moment there's a set of pages which do not have PG_offline
set but kdump would still like to skip, this breaks.

But that's mm guys' call.

--
Regards/Gruss,
Boris.

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