kmem_cache->cpu_partial is just used when CONFIG_SLUB_CPU_PARTIAL is set,
so wrap it with config CONFIG_SLUB_CPU_PARTIAL will save some space
on 32bit arch.
This patch wrap kmem_cache->cpu_partial in config CONFIG_SLUB_CPU_PARTIAL
and wrap its sysfs too.
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
---
include/linux/slub_def.h | 2 ++
mm/slub.c | 72 +++++++++++++++++++++++++++++-------------------
2 files changed, 46 insertions(+), 28 deletions(-)
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 0debd8df1a7d..477ab99800ed 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -69,7 +69,9 @@ struct kmem_cache {
int size; /* The size of an object including meta data */
int object_size; /* The size of an object without meta data */
int offset; /* Free pointer offset. */
+#ifdef CONFIG_SLUB_CPU_PARTIAL
int cpu_partial; /* Number of per cpu partial objects to keep around */
+#endif
struct kmem_cache_order_objects oo;
/* Allocation and freeing of slabs */
diff --git a/mm/slub.c b/mm/slub.c
index fde499b6dad8..94978f27882a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1829,7 +1829,10 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
stat(s, CPU_PARTIAL_NODE);
}
if (!kmem_cache_has_cpu_partial(s)
- || available > s->cpu_partial / 2)
+#ifdef CONFIG_SLUB_CPU_PARTIAL
+ || available > s->cpu_partial / 2
+#endif
+ )
break;
}
@@ -3418,6 +3421,39 @@ static void set_min_partial(struct kmem_cache *s, unsigned long min)
s->min_partial = min;
}
+static void set_cpu_partial(struct kmem_cache *s)
+{
+#ifdef CONFIG_SLUB_CPU_PARTIAL
+ /*
+ * cpu_partial determined the maximum number of objects kept in the
+ * per cpu partial lists of a processor.
+ *
+ * Per cpu partial lists mainly contain slabs that just have one
+ * object freed. If they are used for allocation then they can be
+ * filled up again with minimal effort. The slab will never hit the
+ * per node partial lists and therefore no locking will be required.
+ *
+ * This setting also determines
+ *
+ * A) The number of objects from per cpu partial slabs dumped to the
+ * per node list when we reach the limit.
+ * B) The number of objects in cpu partial slabs to extract from the
+ * per node list when we run out of per cpu objects. We only fetch
+ * 50% to keep some capacity around for frees.
+ */
+ if (!kmem_cache_has_cpu_partial(s))
+ s->cpu_partial = 0;
+ else if (s->size >= PAGE_SIZE)
+ s->cpu_partial = 2;
+ else if (s->size >= 1024)
+ s->cpu_partial = 6;
+ else if (s->size >= 256)
+ s->cpu_partial = 13;
+ else
+ s->cpu_partial = 30;
+#endif
+}
+
/*
* calculate_sizes() determines the order and the distribution of data within
* a slab object.
@@ -3576,33 +3612,7 @@ static int kmem_cache_open(struct kmem_cache *s, unsigned long flags)
*/
set_min_partial(s, ilog2(s->size) / 2);
- /*
- * cpu_partial determined the maximum number of objects kept in the
- * per cpu partial lists of a processor.
- *
- * Per cpu partial lists mainly contain slabs that just have one
- * object freed. If they are used for allocation then they can be
- * filled up again with minimal effort. The slab will never hit the
- * per node partial lists and therefore no locking will be required.
- *
- * This setting also determines
- *
- * A) The number of objects from per cpu partial slabs dumped to the
- * per node list when we reach the limit.
- * B) The number of objects in cpu partial slabs to extract from the
- * per node list when we run out of per cpu objects. We only fetch
- * 50% to keep some capacity around for frees.
- */
- if (!kmem_cache_has_cpu_partial(s))
- s->cpu_partial = 0;
- else if (s->size >= PAGE_SIZE)
- s->cpu_partial = 2;
- else if (s->size >= 1024)
- s->cpu_partial = 6;
- else if (s->size >= 256)
- s->cpu_partial = 13;
- else
- s->cpu_partial = 30;
+ set_cpu_partial(s);
#ifdef CONFIG_NUMA
s->remote_node_defrag_ratio = 1000;
@@ -3989,7 +3999,9 @@ void __kmemcg_cache_deactivate(struct kmem_cache *s)
* Disable empty slabs caching. Used to avoid pinning offline
* memory cgroups by kmem pages that can be freed.
*/
+#ifdef CONFIG_SLUB_CPU_PARTIAL
s->cpu_partial = 0;
+#endif
s->min_partial = 0;
/*
@@ -4929,6 +4941,7 @@ static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
}
SLAB_ATTR(min_partial);
+#ifdef CONFIG_SLUB_CPU_PARTIAL
static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
{
return sprintf(buf, "%u\n", s->cpu_partial);
@@ -4951,6 +4964,7 @@ static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
return length;
}
SLAB_ATTR(cpu_partial);
+#endif
static ssize_t ctor_show(struct kmem_cache *s, char *buf)
{
@@ -5363,7 +5377,9 @@ static struct attribute *slab_attrs[] = {
&objs_per_slab_attr.attr,
&order_attr.attr,
&min_partial_attr.attr,
+#ifdef CONFIG_SLUB_CPU_PARTIAL
&cpu_partial_attr.attr,
+#endif
&objects_attr.attr,
&objects_partial_attr.attr,
&partial_attr.attr,
--
2.11.0
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