Re: [PATCH v2 2/2] mm/vmalloc: Remove gfpflags_allow_blocking() check

From: Michal Hocko
Date: Wed Jul 07 2021 - 04:51:26 EST


On Mon 05-07-21 19:05:37, Uladzislau Rezki (Sony) wrote:
> Get rid of gfpflags_allow_blocking() check from the vmalloc() path
> as it is supposed to be sleepable anyway. Thus remove it from the
> alloc_vmap_area() as well as from the vm_area_alloc_pages().
>
> Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
> mm/vmalloc.c | 18 ++++++++----------
> 1 file changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 5297958ac7c5..93a9cbdba905 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1479,6 +1479,7 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
> int node, gfp_t gfp_mask)
> {
> struct vmap_area *va;
> + unsigned long freed;
> unsigned long addr;
> int purged = 0;
> int ret;
> @@ -1542,13 +1543,12 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
> goto retry;
> }
>
> - if (gfpflags_allow_blocking(gfp_mask)) {
> - unsigned long freed = 0;
> - blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
> - if (freed > 0) {
> - purged = 0;
> - goto retry;
> - }
> + freed = 0;
> + blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
> +
> + if (freed > 0) {
> + purged = 0;
> + goto retry;
> }
>
> if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
> @@ -2834,9 +2834,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
> for (i = 0; i < (1U << order); i++)
> pages[nr_allocated + i] = page + i;
>
> - if (gfpflags_allow_blocking(gfp))
> - cond_resched();
> -
> + cond_resched();
> nr_allocated += 1U << order;
> }
>
> --
> 2.20.1

--
Michal Hocko
SUSE Labs