On 11/25/24 22:01, Matthew Wilcox (Oracle) wrote:
> In preparation for allocating frozen pages, stop initialising the page
> refcount in __alloc_pages_may_oom().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
> ---
> mm/page_alloc.c | 10 ++++------
> 1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index c9e5c69f0cb9..514994cd67b8 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -3638,10 +3638,8 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
> page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
> ~__GFP_DIRECT_RECLAIM, order,
> ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
> - if (page) {
> - set_page_refcounted(page);
> + if (page)
> goto out;
> - }
>
> /* Coredumps can quickly deplete all memory reserves */
> if (current->flags & PF_DUMPCORE)
> @@ -3686,8 +3684,6 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
> if (gfp_mask & __GFP_NOFAIL)
> page = __alloc_pages_cpuset_fallback(gfp_mask, order,
> ALLOC_NO_WATERMARKS, ac);
> - if (page)
> - set_page_refcounted(page);
> }
> out:
> mutex_unlock(&oom_lock);
> @@ -4471,8 +4467,10 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
>
> /* Reclaim has failed us, start killing things */
> page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress);
> - if (page)
> + if (page) {
> + set_page_refcounted(page);
> goto got_pg;
> + }
>
> /* Avoid allocations with no watermarks from looping endlessly */
> if (tsk_is_oom_victim(current) &&
