Re: [Invitation] Linux MM Alignment Session on kmemdump on Wednesday

[Shakeel Butt <shakeel.butt@linux.dev>]

On Tue, Sep 16, 2025 at 03:14:48PM +0300, Eugen Hristev wrote:
> 
> 
> On 9/16/25 15:07, Matthew Wilcox wrote:
> > On Tue, Sep 16, 2025 at 11:49:35AM +0300, Eugen Hristev wrote:
> >> On 9/15/25 21:53, Matthew Wilcox wrote:
> >>> On Mon, Sep 15, 2025 at 08:58:35AM -0700, David Rientjes wrote:
> >>>> This week's topic will be kmemdump led by Eugen Hristev.  See the latest
> >>>> proposal at https://lwn.net/Articles/1031319/.
> >>>
> >>> I don't understand what this has to do with mm, to be honest.
> >>> It looks like a debugging aid.
> >>
> >> It was suggested to move it to mm/ :
> >>
> >> https://lore.kernel.org/all/0fa9e4e7-1247-4c82-8c0b-fa65b7fbb56d@infradead.org/
> > 
> > I feel like you should be able to explain this rather better than
> > "somebody else told me to move it".  As of this moment, I still don't
> > know what kmemdump even is.
> > 
> >>>
> >>> https://lore.kernel.org/lkml/20250422113156.575971-2-eugen.hristev@linaro.org/
> >>>
> >>> is a great example of how to write a lot of documentation that doesn't
> >>> actually tell the reader what anything is.
> >>>
> >>>
> >>
> >> Here is a link to the v3 where I changed it a little bit :
> >>
> >> https://lore.kernel.org/all/20250912150855.2901211-1-eugen.hristev@linaro.org/
> >>
> >> I am eager to improve the documentation to make more sense out of it, I
> >> am happy with suggestions.
> > 
> > Start by telling me what it is.
> 
> A way to select memory areas from the kernel that can be used to debug
> the kernel, instead of saving the whole memory dump which is mostly not
> of interest and takes a lot of space.
> Anyone can register a pointer and a size, these are placed into a list,
> and a dedicated firmware can parse it and save it in case of a crash.
> Does this make sense ?

Is it only for kernel or is available for userspace as well? And the
crashes here, we are talking about kernel crashes or includes process
crashes as well?