Re: [RESEND v2] mm: don't defer struct page initialization for Xen pv guests

[Andrew Morton]

On Fri, 16 Feb 2018 16:41:01 +0100 Juergen Gross <jgross@xxxxxxxx> wrote:

> --- 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;

I'll do this:

--- a/mm/page_alloc.c~mm-dont-defer-struct-page-initialization-for-xen-pv-guests-fix
+++ a/mm/page_alloc.c
@@ -46,6 +46,7 @@
 #include <linux/stop_machine.h>
 #include <linux/sort.h>
 #include <linux/pfn.h>
+#include <xen/xen.h>
 #include <linux/backing-dev.h>
 #include <linux/fault-inject.h>
 #include <linux/page-isolation.h>

So we're not relying on dumb luck ;)