Since slab_alloc_node() is the only caller of __slab_alloc(), embed
__slab_alloc() to its caller to save function call overhead. This
will also expand the caller's code block size a bit, but hackbench
tests on both host and guest didn't show a difference w/ or w/o
this patch.

Also rename ___slab_alloc() to __slab_alloc().

Signed-off-by: Abel Wu <abe...@icloud.com>
---
 mm/slub.c | 46 ++++++++++++++++------------------------------
 1 file changed, 16 insertions(+), 30 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 7ecbbbe5bc0c..0f69d2d0471a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2654,10 +2654,9 @@ static inline void *get_freelist(struct kmem_cache *s, 
struct page *page)
  * we need to allocate a new slab. This is the slowest path since it involves
  * a call to the page allocator and the setup of a new slab.
  *
- * Version of __slab_alloc to use when we know that interrupts are
- * already disabled (which is the case for bulk allocation).
+ * Must be called with interrupts disabled.
  */
-static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
+static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
                          unsigned long addr, struct kmem_cache_cpu *c)
 {
        void *freelist;
@@ -2758,31 +2757,6 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t 
gfpflags, int node,
        return freelist;
 }
 
-/*
- * Another one that disabled interrupt and compensates for possible
- * cpu changes by refetching the per cpu area pointer.
- */
-static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
-                         unsigned long addr, struct kmem_cache_cpu *c)
-{
-       void *p;
-       unsigned long flags;
-
-       local_irq_save(flags);
-#ifdef CONFIG_PREEMPTION
-       /*
-        * We may have been preempted and rescheduled on a different
-        * cpu before disabling interrupts. Need to reload cpu area
-        * pointer.
-        */
-       c = this_cpu_ptr(s->cpu_slab);
-#endif
-
-       p = ___slab_alloc(s, gfpflags, node, addr, c);
-       local_irq_restore(flags);
-       return p;
-}
-
 /*
  * If the object has been wiped upon free, make sure it's fully initialized by
  * zeroing out freelist pointer.
@@ -2854,7 +2828,19 @@ static __always_inline void *slab_alloc_node(struct 
kmem_cache *s,
        object = c->freelist;
        page = c->page;
        if (unlikely(!object || !page || !node_match(page, node))) {
+               unsigned long flags;
+
+               local_irq_save(flags);
+#ifdef CONFIG_PREEMPTION
+               /*
+                * We may have been preempted and rescheduled on a different
+                * cpu before disabling interrupts. Need to reload cpu area
+                * pointer.
+                */
+               c = this_cpu_ptr(s->cpu_slab);
+#endif
                object = __slab_alloc(s, gfpflags, node, addr, c);
+               local_irq_restore(flags);
        } else {
                void *next_object = get_freepointer_safe(s, object);
 
@@ -3299,7 +3285,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t 
flags, size_t size,
                         * We may have removed an object from c->freelist using
                         * the fastpath in the previous iteration; in that case,
                         * c->tid has not been bumped yet.
-                        * Since ___slab_alloc() may reenable interrupts while
+                        * Since __slab_alloc() may reenable interrupts while
                         * allocating memory, we should bump c->tid now.
                         */
                        c->tid = next_tid(c->tid);
@@ -3308,7 +3294,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t 
flags, size_t size,
                         * Invoking slow path likely have side-effect
                         * of re-populating per CPU c->freelist
                         */
-                       p[i] = ___slab_alloc(s, flags, NUMA_NO_NODE,
+                       p[i] = __slab_alloc(s, flags, NUMA_NO_NODE,
                                            _RET_IP_, c);
                        if (unlikely(!p[i]))
                                goto error;
-- 
2.27.0

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