Re: [PATCH v2 01/13] mm/page_alloc: rename ALLOC_TRYLOCK -> ALLOC_NOLOCK

[Suren Baghdasaryan]

On Mon, Jun 22, 2026 at 3:01 AM Brendan Jackman <jackmanb@xxxxxxxxxx> wrote:
>
> It's confusing that the function is called "nolock" but the flag is
> called "trylock", align them.
>
> The function's terminology is more visible and has more mindshare so use that.
>
> Suggested-by: "Vlastimil Babka (SUSE)" <vbabka@xxxxxxxxxx>
> Link: https://lore.kernel.org/linux-mm/2399b3ad-4eac-4a14-94c3-27e9f07972a1@xxxxxxxxxx/
> Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx>

That comment for ALLOC_NOLOCK about only using spin_trylock in the
allocation path could be rewritten to say that no locking or spinning
is allowed but it's a minor detail.

Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>

> ---
>  mm/internal.h   |  2 +-
>  mm/page_alloc.c | 10 +++++-----
>  2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/mm/internal.h b/mm/internal.h
> index 181e79f1d6a20..1483a4fcdfce1 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -1475,7 +1475,7 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone,
>  #define ALLOC_NOFRAGMENT         0x0
>  #endif
>  #define ALLOC_HIGHATOMIC       0x200 /* Allows access to MIGRATE_HIGHATOMIC */
> -#define ALLOC_TRYLOCK          0x400 /* Only use spin_trylock in allocation path */
> +#define ALLOC_NOLOCK           0x400 /* Only use spin_trylock in allocation path */
>  #define ALLOC_KSWAPD           0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
>
>  /* Flags that allow allocations below the min watermark. */
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 0111cdbdb5321..6c4eb6908bd95 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2528,7 +2528,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
>         unsigned long flags;
>         int i;
>
> -       if (unlikely(alloc_flags & ALLOC_TRYLOCK)) {
> +       if (unlikely(alloc_flags & ALLOC_NOLOCK)) {
>                 if (!spin_trylock_irqsave(&zone->lock, flags))
>                         return 0;
>         } else {
> @@ -3216,7 +3216,7 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone,
>
>         do {
>                 page = NULL;
> -               if (unlikely(alloc_flags & ALLOC_TRYLOCK)) {
> +               if (unlikely(alloc_flags & ALLOC_NOLOCK)) {
>                         if (!spin_trylock_irqsave(&zone->lock, flags))
>                                 return NULL;
>                 } else {
> @@ -5042,7 +5042,7 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
>          * Don't invoke should_fail logic, since it may call
>          * get_random_u32() and printk() which need to spin_lock.
>          */
> -       if (!(*alloc_flags & ALLOC_TRYLOCK) &&
> +       if (!(*alloc_flags & ALLOC_NOLOCK) &&
>             should_fail_alloc_page(gfp_mask, order))
>                 return false;
>
> @@ -7786,7 +7786,7 @@ static bool cond_accept_memory(struct zone *zone, unsigned int order,
>                 return false;
>
>         /* Bailout, since try_to_accept_memory_one() needs to take a lock */
> -       if (alloc_flags & ALLOC_TRYLOCK)
> +       if (alloc_flags & ALLOC_NOLOCK)
>                 return false;
>
>         wmark = promo_wmark_pages(zone);
> @@ -7878,7 +7878,7 @@ struct page *alloc_frozen_pages_nolock_noprof(gfp_t gfp_flags, int nid, unsigned
>          */
>         gfp_t alloc_gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_NOMEMALLOC | __GFP_COMP
>                         | gfp_flags;
> -       unsigned int alloc_flags = ALLOC_TRYLOCK;
> +       unsigned int alloc_flags = ALLOC_NOLOCK;
>         struct alloc_context ac = { };
>         struct page *page;
>
>
> --
> 2.54.0
>