[PATCH v3 07/15] mm/slab: pass alloc_flags to new slab allocation

["Vlastimil Babka (SUSE)" <vbabka@kernel.org>]

Add the alloc_flags parameter to allocate_slab() and new_slab()
so it can be used to determine if spinning is allowed, independently
from gfp flags.

refill_objects() passes SLAB_ALLOC_DEFAULT because it can only be
reached from contexts that allow spinning.

Link: https://patch.msgid.link/20260610-slab_alloc_flags-v2-8-7190909db118@kernel.org
Reviewed-by: Hao Li <hao.li@linux.dev>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
---
 mm/slub.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 3a34907b881b..a975a2e727c8 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3378,9 +3378,10 @@ static __always_inline void unaccount_slab(struct slab *slab, int order,
 }
 
 /* Allocate and initialize a slab without building its freelist. */
-static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
+static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags,
+				  unsigned int alloc_flags, int node)
 {
-	bool allow_spin = gfpflags_allow_spinning(flags);
+	bool allow_spin = alloc_flags_allow_spinning(alloc_flags);
 	struct slab *slab;
 	struct kmem_cache_order_objects oo = s->oo;
 	gfp_t alloc_gfp;
@@ -3398,10 +3399,6 @@ static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 	if ((alloc_gfp & __GFP_DIRECT_RECLAIM) && oo_order(oo) > oo_order(s->min))
 		alloc_gfp = (alloc_gfp | __GFP_NOMEMALLOC) & ~__GFP_RECLAIM;
 
-	/*
-	 * __GFP_RECLAIM could be cleared on the first allocation attempt,
-	 * so pass allow_spin flag directly.
-	 */
 	slab = alloc_slab_page(alloc_gfp, node, oo, allow_spin);
 	if (unlikely(!slab)) {
 		oo = s->min;
@@ -3438,15 +3435,17 @@ static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
 	return slab;
 }
 
-static struct slab *new_slab(struct kmem_cache *s, gfp_t flags, int node)
+static struct slab *new_slab(struct kmem_cache *s, gfp_t flags,
+			     unsigned int alloc_flags, int node)
 {
 	if (unlikely(flags & GFP_SLAB_BUG_MASK))
 		flags = kmalloc_fix_flags(flags);
 
 	WARN_ON_ONCE(s->ctor && (flags & __GFP_ZERO));
 
-	return allocate_slab(s,
-		flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
+	flags &= GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK;
+
+	return allocate_slab(s, flags, alloc_flags, node);
 }
 
 static void __free_slab(struct kmem_cache *s, struct slab *slab, bool allow_spin)
@@ -4482,7 +4481,7 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 	if (object)
 		goto success;
 
-	slab = new_slab(s, trynode_flags, node);
+	slab = new_slab(s, trynode_flags, ac->alloc_flags, node);
 
 	if (unlikely(!slab)) {
 		if (node != NUMA_NO_NODE && !(gfpflags & __GFP_THISNODE)
@@ -7230,7 +7229,7 @@ refill_objects(struct kmem_cache *s, void **p, gfp_t gfp, unsigned int min,
 
 new_slab:
 
-	slab = new_slab(s, gfp, local_node);
+	slab = new_slab(s, gfp, SLAB_ALLOC_DEFAULT, local_node);
 	if (!slab)
 		goto out;
 
@@ -7578,7 +7577,7 @@ static void early_kmem_cache_node_alloc(int node)
 
 	BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
 
-	slab = new_slab(kmem_cache_node, GFP_NOWAIT, node);
+	slab = new_slab(kmem_cache_node, GFP_NOWAIT, SLAB_ALLOC_DEFAULT, node);
 
 	BUG_ON(!slab);
 	if (slab_nid(slab) != node) {

-- 
2.54.0