Re: [PATCH v10 1/8] mm: ksm: Export ksm_madvise()

Paul Mackerras
2019-11-06T04:33:29Z

On Mon, Nov 04, 2019 at 09:47:53AM +0530, Bharata B Rao wrote:
> KVM PPC module needs ksm_madvise() for supporting secure guests.
> Guest pages that become secure are represented as device private
> pages in the host. Such pages shouldn't participate in KSM merging.

If we don't do the ksm_madvise call, then as far as I can tell, it
should all still work correctly, but we might have KSM pulling pages
in unnecessarily, causing a reduction in performance. Is that right?

> Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>

Acked-by: Paul Mackerras <paulus@ozlabs.org>