#define SPLAT_KMEM_TEST12_NAME "vmem_size"
#define SPLAT_KMEM_TEST12_DESC "Memory zone test"
+#define SPLAT_KMEM_TEST13_ID 0x010d
+#define SPLAT_KMEM_TEST13_NAME "slab_reclaim"
+#define SPLAT_KMEM_TEST13_DESC "Slab direct memory reclaim test"
+
#define SPLAT_KMEM_ALLOC_COUNT 10
#define SPLAT_VMEM_ALLOC_COUNT 10
kct->kct_kcd_count * sizeof(kmem_cache_data_t *));
}
+static void
+splat_kmem_cache_test_debug(struct file *file, char *name,
+ kmem_cache_priv_t *kcp)
+{
+ int j;
+
+ splat_vprint(file, name,
+ "%s cache objects %d, slabs %u/%u objs %u/%u mags ",
+ kcp->kcp_cache->skc_name, kcp->kcp_count,
+ (unsigned)kcp->kcp_cache->skc_slab_alloc,
+ (unsigned)kcp->kcp_cache->skc_slab_total,
+ (unsigned)kcp->kcp_cache->skc_obj_alloc,
+ (unsigned)kcp->kcp_cache->skc_obj_total);
+
+ for_each_online_cpu(j)
+ splat_print(file, "%u/%u ",
+ kcp->kcp_cache->skc_mag[j]->skm_avail,
+ kcp->kcp_cache->skc_mag[j]->skm_size);
+
+ splat_print(file, "%s\n", "");
+}
+
static int
splat_kmem_cache_test_constructor(void *ptr, void *priv, int flags)
{
{
kmem_cache_priv_t *kcp;
kmem_cache_data_t *kcd;
- int i, j, rc = 0;
+ int i, rc = 0;
kcp = splat_kmem_cache_test_kcp_alloc(file, SPLAT_KMEM_TEST8_NAME,
256, 0, 0, SPLAT_KMEM_OBJ_COUNT);
*/
for (i = 0; i < 60; i++) {
kmem_cache_reap_now(kcp->kcp_cache);
- splat_vprint(file, SPLAT_KMEM_TEST8_NAME,
- "%s cache objects %d, slabs %u/%u objs %u/%u mags ",
- SPLAT_KMEM_CACHE_NAME, kcp->kcp_count,
- (unsigned)kcp->kcp_cache->skc_slab_alloc,
- (unsigned)kcp->kcp_cache->skc_slab_total,
- (unsigned)kcp->kcp_cache->skc_obj_alloc,
- (unsigned)kcp->kcp_cache->skc_obj_total);
-
- for_each_online_cpu(j)
- splat_print(file, "%u/%u ",
- kcp->kcp_cache->skc_mag[j]->skm_avail,
- kcp->kcp_cache->skc_mag[j]->skm_size);
-
- splat_print(file, "%s\n", "");
+ splat_kmem_cache_test_debug(file, SPLAT_KMEM_TEST8_NAME, kcp);
if (kcp->kcp_cache->skc_obj_total == 0)
break;
{
kmem_cache_priv_t *kcp;
kmem_cache_data_t *kcd;
- int i, j, rc = 0, count = SPLAT_KMEM_OBJ_COUNT * 128;
+ int i, rc = 0, count = SPLAT_KMEM_OBJ_COUNT * 128;
kcp = splat_kmem_cache_test_kcp_alloc(file, SPLAT_KMEM_TEST9_NAME,
256, 0, 0, count);
* if it takes longer than this something has gone wrong.
*/
for (i = 0; i < 60; i++) {
- splat_vprint(file, SPLAT_KMEM_TEST9_NAME,
- "%s cache objects %d, slabs %u/%u objs %u/%u mags ",
- SPLAT_KMEM_CACHE_NAME, kcp->kcp_count,
- (unsigned)kcp->kcp_cache->skc_slab_alloc,
- (unsigned)kcp->kcp_cache->skc_slab_total,
- (unsigned)kcp->kcp_cache->skc_obj_alloc,
- (unsigned)kcp->kcp_cache->skc_obj_total);
-
- for_each_online_cpu(j)
- splat_print(file, "%u/%u ",
- kcp->kcp_cache->skc_mag[j]->skm_avail,
- kcp->kcp_cache->skc_mag[j]->skm_size);
-
- splat_print(file, "%s\n", "");
+ splat_kmem_cache_test_debug(file, SPLAT_KMEM_TEST9_NAME, kcp);
if (kcp->kcp_cache->skc_obj_total == 0)
break;
return 0;
}
+typedef struct dummy_page {
+ struct list_head dp_list;
+ char dp_pad[PAGE_SIZE - sizeof(struct list_head)];
+} dummy_page_t;
+
+/*
+ * This test is designed to verify that direct reclaim is functioning as
+ * expected. We allocate a large number of objects thus creating a large
+ * number of slabs. We then apply memory pressure and expect that the
+ * direct reclaim path can easily recover those slabs. The registered
+ * reclaim function will free the objects and the slab shrinker will call
+ * it repeatedly until at least a single slab can be freed.
+ *
+ * Note it may not be possible to reclaim every last slab via direct reclaim
+ * without a failure because the shrinker_rwsem may be contended. For this
+ * reason, quickly reclaiming 3/4 of the slabs is considered a success.
+ *
+ * This should all be possible within 10 seconds. For reference, on a
+ * system with 2G of memory this test takes roughly 0.2 seconds to run.
+ * It may take longer on larger memory systems but should still easily
+ * complete in the alloted 10 seconds.
+ */
+static int
+splat_kmem_test13(struct file *file, void *arg)
+{
+ kmem_cache_priv_t *kcp;
+ kmem_cache_data_t *kcd;
+ dummy_page_t *dp;
+ struct list_head list;
+ struct timespec start, delta;
+ int size, count, slabs, fails = 0;
+ int i, rc = 0, max_time = 10;
+
+ size = 128 * 1024;
+ count = ((physmem * PAGE_SIZE) / 4 / size);
+
+ kcp = splat_kmem_cache_test_kcp_alloc(file, SPLAT_KMEM_TEST13_NAME,
+ size, 0, 0, count);
+ if (!kcp) {
+ splat_vprint(file, SPLAT_KMEM_TEST13_NAME,
+ "Unable to create '%s'\n", "kcp");
+ return -ENOMEM;
+ }
+
+ kcp->kcp_cache =
+ kmem_cache_create(SPLAT_KMEM_CACHE_NAME, kcp->kcp_size, 0,
+ splat_kmem_cache_test_constructor,
+ splat_kmem_cache_test_destructor,
+ splat_kmem_cache_test_reclaim,
+ kcp, NULL, 0);
+ if (!kcp->kcp_cache) {
+ splat_kmem_cache_test_kcp_free(kcp);
+ splat_vprint(file, SPLAT_KMEM_TEST13_NAME,
+ "Unable to create '%s'\n", SPLAT_KMEM_CACHE_NAME);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < count; i++) {
+ kcd = kmem_cache_alloc(kcp->kcp_cache, KM_SLEEP);
+ spin_lock(&kcp->kcp_lock);
+ kcp->kcp_kcd[i] = kcd;
+ spin_unlock(&kcp->kcp_lock);
+ if (!kcd) {
+ splat_vprint(file, SPLAT_KMEM_TEST13_NAME,
+ "Unable to allocate from '%s'\n",
+ SPLAT_KMEM_CACHE_NAME);
+ }
+ }
+
+ i = 0;
+ slabs = kcp->kcp_cache->skc_slab_total;
+ INIT_LIST_HEAD(&list);
+ start = current_kernel_time();
+
+ while (kcp->kcp_cache->skc_slab_total > (slabs >> 2)) {
+
+ if ((i % 10000) == 0)
+ splat_kmem_cache_test_debug(
+ file, SPLAT_KMEM_TEST13_NAME, kcp);
+
+ delta = timespec_sub(current_kernel_time(), start);
+ if (delta.tv_sec >= max_time) {
+ splat_vprint(file, SPLAT_KMEM_TEST13_NAME,
+ "Failed to reclaim 3/4 of cache in %ds, "
+ "%u/%u slabs remain\n", max_time,
+ (unsigned)kcp->kcp_cache->skc_slab_total,
+ slabs);
+ rc = -ETIME;
+ break;
+ }
+
+ dp = (dummy_page_t *)__get_free_page(GFP_KERNEL | __GFP_NORETRY);
+ if (!dp) {
+ fails++;
+ splat_vprint(file, SPLAT_KMEM_TEST13_NAME,
+ "Failed (%d) to allocate page with %u "
+ "slabs still in the cache\n", fails,
+ (unsigned)kcp->kcp_cache->skc_slab_total);
+ continue;
+ }
+
+ list_add(&dp->dp_list, &list);
+ i++;
+ }
+
+ if (rc == 0)
+ splat_vprint(file, SPLAT_KMEM_TEST13_NAME,
+ "Successfully created %u slabs and with %d alloc "
+ "failures reclaimed 3/4 of them in %d.%03ds\n",
+ slabs, fails,
+ (int)delta.tv_sec, (int)delta.tv_nsec / 1000000);
+
+ /* Release memory pressure pages */
+ while (!list_empty(&list)) {
+ dp = list_entry(list.next, dummy_page_t, dp_list);
+ list_del_init(&dp->dp_list);
+ free_page((unsigned long)dp);
+ }
+
+ /* Release remaining kmem cache objects */
+ spin_lock(&kcp->kcp_lock);
+ for (i = 0; i < count; i++)
+ if (kcp->kcp_kcd[i])
+ kmem_cache_free(kcp->kcp_cache, kcp->kcp_kcd[i]);
+ spin_unlock(&kcp->kcp_lock);
+
+ kmem_cache_destroy(kcp->kcp_cache);
+ splat_kmem_cache_test_kcp_free(kcp);
+
+ return rc;
+}
+
splat_subsystem_t *
splat_kmem_init(void)
{
#endif /* _LP64 */
SPLAT_TEST_INIT(sub, SPLAT_KMEM_TEST12_NAME, SPLAT_KMEM_TEST12_DESC,
SPLAT_KMEM_TEST12_ID, splat_kmem_test12);
+ SPLAT_TEST_INIT(sub, SPLAT_KMEM_TEST13_NAME, SPLAT_KMEM_TEST13_DESC,
+ SPLAT_KMEM_TEST13_ID, splat_kmem_test13);
return sub;
}
splat_kmem_fini(splat_subsystem_t *sub)
{
ASSERT(sub);
+ SPLAT_TEST_FINI(sub, SPLAT_KMEM_TEST13_ID);
SPLAT_TEST_FINI(sub, SPLAT_KMEM_TEST12_ID);
#ifdef _LP64
SPLAT_TEST_FINI(sub, SPLAT_KMEM_TEST11_ID);
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