Commit 6dfd1b65 authored by Tobin C. Harding's avatar Tobin C. Harding Committed by Linus Torvalds
Browse files

slub: add comments to endif pre-processor macros 

SLUB allocator makes heavy use of ifdef/endif pre-processor macros.  The
pairing of these statements is at times hard to follow e.g.  if the pair
are further than a screen apart or if there are nested pairs.  We can
reduce cognitive load by adding a comment to the endif statement of form

       #ifdef CONFIG_FOO
       ...
       #endif /* CONFIG_FOO */

Add comments to endif pre-processor macros if ifdef/endif pair is not
immediately apparent.

Link: http://lkml.kernel.org/r/20190402230545.2929-5-tobin@kernel.org


Signed-off-by: default avatarTobin C. Harding <tobin@kernel.org>
Acked-by: default avatarChristoph Lameter <cl@linux.com>
Reviewed-by: default avatarRoman Gushchin <guro@fb.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent adab7b68

mm/slub.c

+10 −10
Original line number Diff line number Diff line
@@ -1942,7 +1942,7 @@ static void *get_any_partial(struct kmem_cache *s, gfp_t flags, 
			}

		}

	} while (read_mems_allowed_retry(cpuset_mems_cookie));

#endif

#endif	/* CONFIG_NUMA */

	return NULL;

}
@@ -2240,7 +2240,7 @@ static void unfreeze_partials(struct kmem_cache *s, 
		discard_slab(s, page);

		stat(s, FREE_SLAB);

	}

#endif

#endif	/* CONFIG_SLUB_CPU_PARTIAL */

}



/*
@@ -2299,7 +2299,7 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) 
		local_irq_restore(flags);

	}

	preempt_enable();

#endif

#endif	/* CONFIG_SLUB_CPU_PARTIAL */

}



static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
@@ -2804,7 +2804,7 @@ void *kmem_cache_alloc_node_trace(struct kmem_cache *s, 
}

EXPORT_SYMBOL(kmem_cache_alloc_node_trace);

#endif

#endif

#endif	/* CONFIG_NUMA */



/*

 * Slow path handling. This may still be called frequently since objects
@@ -3839,7 +3839,7 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node) 
	return ret;

}

EXPORT_SYMBOL(__kmalloc_node);

#endif

#endif	/* CONFIG_NUMA */



#ifdef CONFIG_HARDENED_USERCOPY

/*
@@ -4057,7 +4057,7 @@ void __kmemcg_cache_deactivate(struct kmem_cache *s) 
	 */

	slab_deactivate_memcg_cache_rcu_sched(s, kmemcg_cache_deact_after_rcu);

}

#endif

#endif	/* CONFIG_MEMCG */



static int slab_mem_going_offline_callback(void *arg)

{
@@ -4690,7 +4690,7 @@ static int list_locations(struct kmem_cache *s, char *buf, 
		len += sprintf(buf, "No data\n");

	return len;

}

#endif

#endif	/* CONFIG_SLUB_DEBUG */



#ifdef SLUB_RESILIENCY_TEST

static void __init resiliency_test(void)
@@ -4750,7 +4750,7 @@ static void __init resiliency_test(void) 
#ifdef CONFIG_SYSFS

static void resiliency_test(void) {};

#endif

#endif

#endif	/* SLUB_RESILIENCY_TEST */



#ifdef CONFIG_SYSFS

enum slab_stat_type {
@@ -5407,7 +5407,7 @@ STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc); 
STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free);

STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node);

STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain);

#endif

#endif	/* CONFIG_SLUB_STATS */



static struct attribute *slab_attrs[] = {

	&slab_size_attr.attr,
@@ -5608,7 +5608,7 @@ static void memcg_propagate_slab_attrs(struct kmem_cache *s) 


	if (buffer)

		free_page((unsigned long)buffer);

#endif

#endif	/* CONFIG_MEMCG */

}



static void kmem_cache_release(struct kobject *k)

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