[RFC 01/15] slub: Create sysfs field /sys/slab/<cache>/ops

["Tobin C. Harding" <tobin@kernel.org>]

Create an ops field in /sys/slab/*/ops to contain all the callback
operations defined for a slab cache. This will be used to display
the additional callbacks that will be defined soon to enable movable
objects.

Display the existing ctor callback in the ops fields contents.

Co-developed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
---
 mm/slub.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index dc777761b6b7..69164aa7cbbf 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5009,13 +5009,18 @@ static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
 }
 SLAB_ATTR(cpu_partial);
 
-static ssize_t ctor_show(struct kmem_cache *s, char *buf)
+static ssize_t ops_show(struct kmem_cache *s, char *buf)
 {
+	int x = 0;
+
 	if (!s->ctor)
 		return 0;
-	return sprintf(buf, "%pS\n", s->ctor);
+
+	if (s->ctor)
+		x += sprintf(buf + x, "ctor : %pS\n", s->ctor);
+	return x;
 }
-SLAB_ATTR_RO(ctor);
+SLAB_ATTR_RO(ops);
 
 static ssize_t aliases_show(struct kmem_cache *s, char *buf)
 {
@@ -5428,7 +5433,7 @@ static struct attribute *slab_attrs[] = {
 	&objects_partial_attr.attr,
 	&partial_attr.attr,
 	&cpu_slabs_attr.attr,
-	&ctor_attr.attr,
+	&ops_attr.attr,
 	&aliases_attr.attr,
 	&align_attr.attr,
 	&hwcache_align_attr.attr,
-- 
2.21.0