On Wed, 4 May 2022, Zach O'Keefe wrote:
> Add enforce_young flag to struct collapse_control that allows context to
> ignore requirement that some pages in region being collapsed be young or
> referenced. Set this flag in khugepaged collapse context to preserve
> existing khugepaged behavior.
>
> This flag will be used (unset) when introducing madvise collapse
> context since here, the user presumably has reason to believe the
> collapse will be beneficial and khugepaged heuristics shouldn't tell
> the user they are wrong.
>
> Signed-off-by: Zach O'Keefe <zokeefe@xxxxxxxxxx>
> ---
> mm/khugepaged.c | 23 +++++++++++++++--------
> 1 file changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index ca730aec0e3e..b14807b7002e 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -90,6 +90,9 @@ struct collapse_control {
> /* Respect khugepaged_max_ptes_[none|swap|shared] */
> bool enforce_pte_scan_limits;
>
> + /* Require memory to be young */
> + bool enforce_young;
> +
> /* Num pages scanned per node */
> int node_load[MAX_NUMNODES];
>
Small nit: is it possible to unify these into a single bool khugepaged
flag?
Either way:
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
