[patch 40/86] lib/test_meminit.c: add bulk alloc/free tests

Andrew Morton
2019-12-05T00:51:56Z

From: Laura Abbott <labbott@redhat.com>
Subject: lib/test_meminit.c: add bulk alloc/free tests

kmem_cache_alloc_bulk/kmem_cache_free_bulk are used to make multiple
allocations of the same size to avoid the overhead of multiple
kmalloc/kfree calls. Extend the kmem_cache tests to make some calls to
these APIs.

Link: http://lkml.kernel.org/r/20191107191447.23058-1-labbott@redhat.com
Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Alexander Potapenko <glider@google.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Sandeep Patil <sspatil@android.com>
Cc: Jann Horn <jannh@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

lib/test_meminit.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

--- a/lib/test_meminit.c~lib-test_meminitc-add-bulk-alloc-free-tests
+++ a/lib/test_meminit.c
@@ -183,6 +183,9 @@ static bool __init check_buf(void *buf,
return fail;
}

+#define BULK_SIZE 100
+static void *bulk_array[BULK_SIZE];
+
/*
* Test kmem_cache with given parameters:
* want_ctor - use a constructor;
@@ -203,9 +206,24 @@ static int __init do_kmem_cache_size(siz
want_rcu ? SLAB_TYPESAFE_BY_RCU : 0,
want_ctor ? test_ctor : NULL);
for (iter = 0; iter < 10; iter++) {
+ /* Do a test of bulk allocations */
+ if (!want_rcu && !want_ctor) {
+ int ret;
+
+ ret = kmem_cache_alloc_bulk(c, alloc_mask, BULK_SIZE, bulk_array);
+ if (!ret) {
+ fail = true;
+ } else {
+ int i;
+ for (i = 0; i < ret; i++)
+ fail |= check_buf(bulk_array[i], size, want_ctor, want_rcu, want_zero);
+ kmem_cache_free_bulk(c, ret, bulk_array);
+ }
+ }
+
buf = kmem_cache_alloc(c, alloc_mask);
/* Check that buf is zeroed, if it must be. */
- fail = check_buf(buf, size, want_ctor, want_rcu, want_zero);
+ fail |= check_buf(buf, size, want_ctor, want_rcu, want_zero);
fill_with_garbage_skip(buf, size, want_ctor ? CTOR_BYTES : 0);

if (!want_rcu) {
_