mm/slab: replace struct partial_context with slab_alloc_context

Refactor get_from_partial_node(), get_from_any_partial(),
get_from_partial() and ___slab_alloc().

Remove struct partial_context, which used to be more substantial but
shrank as part of the sheaves conversion. Instead pass gfp_flags and
pointer to the new slab_alloc_context, which together is a superset of
partial_context, and alloc_flags are about to be added to
slab_alloc_context as well.

No functional change intended.

Link: https://patch.msgid.link/20260610-slab_alloc_flags-v2-7-7190909db118@kernel.org
Reviewed-by: Harry Yoo (Oracle) <harry@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>

diff --git a/mm/slub.c b/mm/slub.c
index c53592baa0272bd2e763b9d4fe67072b3df75b36..6f6c15d796e183ad73213e14a54b3aa0c12d07d3 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -219,12 +219,6 @@ struct slab_alloc_context {
        size_t orig_size;
 };
 
-/* Structure holding parameters for get_from_partial() call chain */
-struct partial_context {
-       gfp_t flags;
-       unsigned int orig_size;
-};
-
 /* Structure holding parameters for get_partial_node_bulk() */
 struct partial_bulk_context {
        gfp_t flags;
@@ -3825,7 +3819,8 @@ static bool get_partial_node_bulk(struct kmem_cache *s,
  */
 static void *get_from_partial_node(struct kmem_cache *s,
                                   struct kmem_cache_node *n,
-                                  struct partial_context *pc)
+                                  gfp_t gfp_flags,
+                                  const struct slab_alloc_context *ac)
 {
        struct slab *slab, *slab2;
        unsigned long flags;
@@ -3840,7 +3835,7 @@ static void *get_from_partial_node(struct kmem_cache *s,
        if (!n || !n->nr_partial)
                return NULL;
 
-       if (gfpflags_allow_spinning(pc->flags))
+       if (gfpflags_allow_spinning(gfp_flags))
                spin_lock_irqsave(&n->list_lock, flags);
        else if (!spin_trylock_irqsave(&n->list_lock, flags))
                return NULL;
@@ -3848,12 +3843,12 @@ static void *get_from_partial_node(struct kmem_cache *s,
 
                struct freelist_counters old, new;
 
-               if (!pfmemalloc_match(slab, pc->flags))
+               if (!pfmemalloc_match(slab, gfp_flags))
                        continue;
 
                if (IS_ENABLED(CONFIG_SLUB_TINY) || kmem_cache_debug(s)) {
                        object = alloc_single_from_partial(s, n, slab,
-                                                       pc->orig_size);
+                                                       ac->orig_size);
                        if (object)
                                break;
                        continue;
@@ -3887,15 +3882,16 @@ static void *get_from_partial_node(struct kmem_cache *s,
 /*
  * Get an object from somewhere. Search in increasing NUMA distances.
  */
-static void *get_from_any_partial(struct kmem_cache *s, struct partial_context *pc)
+static void *get_from_any_partial(struct kmem_cache *s, gfp_t gfp_flags,
+                                 const struct slab_alloc_context *ac)
 {
 #ifdef CONFIG_NUMA
        struct zonelist *zonelist;
        struct zoneref *z;
        struct zone *zone;
-       enum zone_type highest_zoneidx = gfp_zone(pc->flags);
+       enum zone_type highest_zoneidx = gfp_zone(gfp_flags);
        unsigned int cpuset_mems_cookie;
-       bool allow_spin = gfpflags_allow_spinning(pc->flags);
+       bool allow_spin = gfpflags_allow_spinning(gfp_flags);
 
        /*
         * The defrag ratio allows a configuration of the tradeoffs between
@@ -3929,16 +3925,17 @@ static void *get_from_any_partial(struct kmem_cache *s, struct partial_context *
                if (allow_spin)
                        cpuset_mems_cookie = read_mems_allowed_begin();
 
-               zonelist = node_zonelist(mempolicy_slab_node(), pc->flags);
+               zonelist = node_zonelist(mempolicy_slab_node(), gfp_flags);
                for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
                        struct kmem_cache_node *n;
 
                        n = get_node(s, zone_to_nid(zone));
 
-                       if (n && cpuset_zone_allowed(zone, pc->flags) &&
+                       if (n && cpuset_zone_allowed(zone, gfp_flags) &&
                                        n->nr_partial > s->min_partial) {
 
-                               void *object = get_from_partial_node(s, n, pc);
+                               void *object = get_from_partial_node(s, n,
+                                                               gfp_flags, ac);
 
                                if (object) {
                                        /*
@@ -3960,8 +3957,8 @@ static void *get_from_any_partial(struct kmem_cache *s, struct partial_context *
 /*
  * Get an object from a partial slab
  */
-static void *get_from_partial(struct kmem_cache *s, int node,
-                             struct partial_context *pc)
+static void *get_from_partial(struct kmem_cache *s, int node, gfp_t flags,
+                             const struct slab_alloc_context *ac)
 {
        int searchnode = node;
        void *object;
@@ -3969,11 +3966,11 @@ static void *get_from_partial(struct kmem_cache *s, int node,
        if (node == NUMA_NO_NODE)
                searchnode = numa_mem_id();
 
-       object = get_from_partial_node(s, get_node(s, searchnode), pc);
-       if (object || (node != NUMA_NO_NODE && (pc->flags & __GFP_THISNODE)))
+       object = get_from_partial_node(s, get_node(s, searchnode), flags, ac);
+       if (object || (node != NUMA_NO_NODE && (flags & __GFP_THISNODE)))
                return object;
 
-       return get_from_any_partial(s, pc);
+       return get_from_any_partial(s, flags, ac);
 }
 
 static bool has_pcs_used(int cpu, struct kmem_cache *s)
@@ -4453,21 +4450,21 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
                           const struct slab_alloc_context *ac)
 {
        bool allow_spin = gfpflags_allow_spinning(gfpflags);
+       gfp_t trynode_flags;
        void *object;
        struct slab *slab;
-       struct partial_context pc;
        bool try_thisnode = true;
 
        stat(s, ALLOC_SLOWPATH);
 
 new_objects:
 
-       pc.flags = gfpflags;
+       trynode_flags = gfpflags;
        /*
         * When a preferred node is indicated but no __GFP_THISNODE
         *
         * 1) try to get a partial slab from target node only by having
-        *    __GFP_THISNODE in pc.flags for get_from_partial()
+        *    __GFP_THISNODE in trynode_flags for get_from_partial()
         * 2) if 1) failed, try to allocate a new slab from target node with
         *    GPF_NOWAIT | __GFP_THISNODE opportunistically
         * 3) if 2) failed, retry with original gfpflags which will allow
@@ -4478,17 +4475,16 @@ new_objects:
                     && try_thisnode)) {
                if (unlikely(!allow_spin))
                        /* Do not upgrade gfp to NOWAIT from more restrictive mode */
-                       pc.flags = gfpflags | __GFP_THISNODE;
+                       trynode_flags = gfpflags | __GFP_THISNODE;
                else
-                       pc.flags = GFP_NOWAIT | __GFP_THISNODE;
+                       trynode_flags = GFP_NOWAIT | __GFP_THISNODE;
        }
 
-       pc.orig_size = ac->orig_size;
-       object = get_from_partial(s, node, &pc);
+       object = get_from_partial(s, node, trynode_flags, ac);
        if (object)
                goto success;
 
-       slab = new_slab(s, pc.flags, node);
+       slab = new_slab(s, trynode_flags, node);
 
        if (unlikely(!slab)) {
                if (node != NUMA_NO_NODE && !(gfpflags & __GFP_THISNODE)