Re: [PATCH] pstore: ramoops: support pmsg size larger than kmalloc limitation

[Greg KH]

On Tue, Jun 27, 2023 at 01:25:41PM -0700, Yuxiao Zhang wrote:
> Current pmsg implementation is using kmalloc for pmsg record buffer,
> which has max size limits based on page size.

What is that max size?

> Currently even we
> allocate enough space with pmsg-size, pmsg will still fail if the
> file size is larger than what kmalloc allowed.
> 
> Since we don't need physical contiguous memory for pmsg buffer
> , we can use kvmalloc to avoid such limitation.

Odd placement of the ',' character :)

Anyway, thanks for getting this sent out.

But, what in-kernel user is hitting this in the pstore implementation?
How big of a buffer is it trying to create?  Is this a bug in older
kernels with the in-kernel drivers as well?  If so, should it go to
stable releases and how far back?

thanks,

greg k-h