[CC Pavel]
On Fri 16-02-18 14:37:26, Juergen Gross wrote:
> Commit f7f99100d8d95dbcf09e0216a143211e79418b9f ("mm: stop zeroing
> memory during allocation in vmemmap") broke Xen pv domains in some
> configurations, as the "Pinned" information in struct page of early
> page tables could get lost.
Could you be more specific please?
> Avoid this problem by not deferring struct page initialization when
> running as Xen pv guest.
>
> Cc: <stable@xxxxxxxxxxxxxxx> #4.15
Fixes: f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap")
please
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> ---
> mm/page_alloc.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 81e18ceef579..681d504b9a40 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -347,6 +347,9 @@ static inline bool update_defer_init(pg_data_t *pgdat,
> /* Always populate low zones for address-constrained allocations */
> if (zone_end < pgdat_end_pfn(pgdat))
> return true;
> + /* Xen PV domains need page structures early */
> + if (xen_pv_domain())
> + return true;
> (*nr_initialised)++;
> if ((*nr_initialised > pgdat->static_init_pgcnt) &&
> (pfn & (PAGES_PER_SECTION - 1)) == 0) {
> --
> 2.13.6
--
Michal Hocko
SUSE Labs