diff mbox series

[RFC,2/2] mm, sl[aou]b: test whether kmalloc() alignment works as expected

Message ID 20190319211108.15495-3-vbabka@suse.cz (mailing list archive)
State New, archived
Headers show
Series guarantee natural alignment for kmalloc() | expand

Commit Message

Vlastimil Babka March 19, 2019, 9:11 p.m. UTC
Quick and dirty init test that kmalloc() alignment works as expected for
power-of-two sizes after the previous patch.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
 mm/slab_common.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

Comments

Christoph Lameter (Ampere) March 20, 2019, 12:44 a.m. UTC | #1
On Tue, 19 Mar 2019, Vlastimil Babka wrote:

> Quick and dirty init test that kmalloc() alignment works as expected for
> power-of-two sizes after the previous patch.

There is already an allocator testing function in mm/slub.c. Can you
generalize it or portions and put the into mm/slab_common.c?
diff mbox series

Patch

diff --git a/mm/slab_common.c b/mm/slab_common.c
index e591d5688558..de10ca9640e0 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1621,3 +1621,22 @@  int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
 	return 0;
 }
 ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
+
+static int __init slab_kmalloc_test(void)
+{
+	int i;
+
+	for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
+		unsigned int size = 1 << i;
+		void * obj = kmalloc(size, GFP_KERNEL);
+		unsigned long objaddr = (unsigned long) obj;
+
+		printk("Size %u obj %px alignment: %s", size, obj,
+			(((objaddr & (size - 1)) == 0) ? "OK" : "WRONG"));
+		kfree(obj);
+	}
+
+	return 0;
+}
+
+__initcall(slab_kmalloc_test);