[PATCH v3 02/16] mm/page_alloc: some renames to clarify alloc_flags scopes

From: Brendan Jackman

Date: Mon Jun 29 2026 - 09:26:41 EST


It's pretty confusing that:

- The slowpath and fastpath have a totally distinct set of alloc_flags.

- gfp_to_alloc_flags() sounds generic but it only influences the
slowpath.

Rename some variables to highlight which alloc_flags are
fastpath-specific. Rename gfp_to_alloc_flags() to highlight that it's
slowpath-specific.

gfp_to_alloc_flags_cma() and gfp_to_alloc_flags_nonblocking() currently
have perfectly harmless names, but to keep the naming consistent also
rename those to the alloc_flags_*() pattern (which already exists for
alloc_flags_nofragment()).

Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
---
mm/page_alloc.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 421271849f291..6010693861ec2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3774,8 +3774,8 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
}

/* Must be called after current_gfp_context() which can change gfp_mask */
-static inline unsigned int gfp_to_alloc_flags_cma(gfp_t gfp_mask,
- unsigned int alloc_flags)
+static inline unsigned int alloc_flags_cma(gfp_t gfp_mask,
+ unsigned int alloc_flags)
{
#ifdef CONFIG_CMA
if (gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE)
@@ -4474,7 +4474,7 @@ static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
}

static inline unsigned int
-gfp_to_alloc_flags_nonblocking(gfp_t gfp_mask, unsigned int order)
+alloc_flags_nonblocking(gfp_t gfp_mask, unsigned int order)
{
unsigned int alloc_flags = 0;

@@ -4497,7 +4497,7 @@ gfp_to_alloc_flags_nonblocking(gfp_t gfp_mask, unsigned int order)
}

static inline unsigned int
-gfp_to_alloc_flags(gfp_t gfp_mask, unsigned int order)
+alloc_flags_slowpath(gfp_t gfp_mask, unsigned int order)
{
unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;

@@ -4512,7 +4512,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask, unsigned int order)
if (gfp_mask & __GFP_KSWAPD_RECLAIM)
alloc_flags |= ALLOC_KSWAPD;

- alloc_flags |= gfp_to_alloc_flags_nonblocking(gfp_mask, order);
+ alloc_flags |= alloc_flags_nonblocking(gfp_mask, order);

if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) {
/*
@@ -4525,7 +4525,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask, unsigned int order)
} else if (unlikely(rt_or_dl_task(current)) && in_task())
alloc_flags |= ALLOC_MIN_RESERVE;

- alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, alloc_flags);
+ alloc_flags = alloc_flags_cma(gfp_mask, alloc_flags);

if (defrag_mode)
alloc_flags |= ALLOC_NOFRAGMENT;
@@ -4791,7 +4791,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
* kswapd needs to be woken up, and to avoid the cost of setting up
* alloc_flags precisely. So we do that now.
*/
- alloc_flags = gfp_to_alloc_flags(gfp_mask, order);
+ alloc_flags = alloc_flags_slowpath(gfp_mask, order);

/*
* We need to recalculate the starting point for the zonelist iterator
@@ -4832,7 +4832,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,

reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
if (reserve_flags)
- alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags) |
+ alloc_flags = alloc_flags_cma(gfp_mask, reserve_flags) |
(alloc_flags & ALLOC_KSWAPD);

/*
@@ -5063,7 +5063,7 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
should_fail_alloc_page(gfp_mask, order))
return false;

- *alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, *alloc_flags);
+ *alloc_flags = alloc_flags_cma(gfp_mask, *alloc_flags);

/* Dirty zone balancing only done in the fast path */
ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE);
@@ -5277,7 +5277,7 @@ struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order,
int preferred_nid, nodemask_t *nodemask)
{
struct page *page;
- unsigned int alloc_flags = ALLOC_WMARK_LOW;
+ unsigned int fastpath_alloc_flags = ALLOC_WMARK_LOW;
gfp_t alloc_gfp; /* The gfp_t that was actually used for allocation */
struct alloc_context ac = { };

@@ -5299,18 +5299,18 @@ struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order,
gfp = current_gfp_context(gfp);
alloc_gfp = gfp;
if (!prepare_alloc_pages(gfp, order, preferred_nid, nodemask, &ac,
- &alloc_gfp, &alloc_flags))
+ &alloc_gfp, &fastpath_alloc_flags))
return NULL;

/*
* Forbid the first pass from falling back to types that fragment
* memory until all local zones are considered.
*/
- alloc_flags |= alloc_flags_nofragment(zonelist_zone(ac.preferred_zoneref), gfp);
- alloc_flags |= gfp_to_alloc_flags_nonblocking(gfp, order) & ALLOC_HIGHATOMIC;
+ fastpath_alloc_flags |= alloc_flags_nofragment(zonelist_zone(ac.preferred_zoneref), gfp);
+ fastpath_alloc_flags |= alloc_flags_nonblocking(gfp, order) & ALLOC_HIGHATOMIC;

/* First allocation attempt */
- page = get_page_from_freelist(alloc_gfp, order, alloc_flags, &ac);
+ page = get_page_from_freelist(alloc_gfp, order, fastpath_alloc_flags, &ac);
if (likely(page))
goto out;


--
2.54.0