Keep SHM_LARGE_FRAG_SIZE fixed a 32 KiB for release & debug. Fixes unit-test bug.

Author: gapisback

src/platform_linux/shmem.c

@@ -57,20 +57,6 @@ typedef struct shm_frag_info {
    int      shm_line;
 } shm_frag_info;
 
-/*
- * All memory allocations of this size or larger will be tracked in the
- * above fragment tracker array. For large inserts workload, we allocate large
- * memory chunks for fingerprint array, which is more than a MiB. For scans,
- * splinterdb_iterator_init() allocates memory for an iterator which is ~92+KiB.
- * Set this to a lower value so we can re-cycle free fragments for iterators
- * also.
- */
-#if SPLINTER_DEBUG
-#   define SHM_LARGE_FRAG_SIZE (90 * KiB)
-#else
-#   define SHM_LARGE_FRAG_SIZE (38 * KiB)
-#endif // SPLINTER_DEBUG
-
 /*
  * In the worst case we may have all threads performing activities that need
  * such large memory fragments. We track up to twice the # of configured

src/platform_linux/shmem.h

@@ -8,6 +8,17 @@
 
 typedef struct shmem_info shmem_info;
 
+/*
+ * All memory allocations of this size or larger will be tracked in the
+ * a fragment tracker array. For large inserts workload, we allocate large
+ * memory chunks for fingerprint array, which is more than a MiB. For scans,
+ * splinterdb_iterator_init() allocates memory for an iterator which is ~42+KiB.
+ * Set this to a lower value so we can re-cycle free fragments for iterators
+ * also. (Keep the limit same for release/debug builds to get consistent
+ * behaviour.)
+ */
+#define SHM_LARGE_FRAG_SIZE (32 * KiB)
+
 platform_status
 platform_shmcreate(size_t                size,
                    platform_heap_handle *heap_handle,

tests/unit/platform_apis_test.c

@@ -267,15 +267,30 @@ CTEST2(platform_api, test_large_TYPED_MALLOC)
    platform_free(data->hid, iter);
 }
 
+/*
+ * Basic test case to verify that memory for large fragments is being
+ * recycled as expected.
+ */
 CTEST2(platform_api, test_large_TYPED_MALLOC_free_and_MALLOC)
 {
-   trunk_range_iterator *iter      = TYPED_MALLOC(data->hid, iter);
+   trunk_range_iterator *iter = TYPED_MALLOC(data->hid, iter);
+   // This struct should be larger than the threshold at which large
+   // free fragment strategy kicks-in.
+   ASSERT_TRUE(sizeof(*iter) >= SHM_LARGE_FRAG_SIZE);
+
    trunk_range_iterator *save_iter = iter;
    platform_free(data->hid, iter);
 
    trunk_range_iterator *new_iter = TYPED_MALLOC(data->hid, iter);
+
    // Memory for large structures should be recycled from shared memory
-   ASSERT_TRUE(!data->use_shmem || (save_iter == new_iter));
+   ASSERT_TRUE(!data->use_shmem || (save_iter == new_iter),
+               "use_shmem=%d, save_iter=%p, new_iter=%p"
+               ", sizeof() requested struct=%lu",
+               data->use_shmem,
+               save_iter,
+               new_iter,
+               sizeof(*iter));
    platform_free(data->hid, new_iter);
 }