[PATCH v4 1/3] memblock test: Add test to memblock_add() 129th region

From: shaoqin . huang
Date: Sun Sep 18 2022 - 22:49:32 EST


From: Shaoqin Huang <shaoqin.huang@xxxxxxxxx>

Add 129th region into the memblock, and this will trigger the
memblock_double_array() function, this needs valid memory regions. So
using dummy_physical_memory_init() to allocate a large enough memory
region, and split it into a large enough memory which can be choosed by
memblock_double_array(), and the left memory will be split into small
memory region, and add them into the memblock. It make sure the
memblock_double_array() will always choose the valid memory region that
is allocated by the dummy_physical_memory_init().
So memblock_double_array() must success.

Another thing should be done is to restore the memory.regions after
memblock_double_array(), due to now the memory.regions is pointing to a
memory region allocated by dummy_physical_memory_init(). And it will
affect the subsequent tests if we don't restore the memory region. So
simply record the origin region, and restore it after the test.

Signed-off-by: Shaoqin Huang <shaoqin.huang@xxxxxxxxx>
---
tools/testing/memblock/tests/basic_api.c | 93 ++++++++++++++++++++++++
tools/testing/memblock/tests/common.c | 7 +-
tools/testing/memblock/tests/common.h | 6 +-
3 files changed, 103 insertions(+), 3 deletions(-)

diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
index a13a57ba0815..4d61a4b474be 100644
--- a/tools/testing/memblock/tests/basic_api.c
+++ b/tools/testing/memblock/tests/basic_api.c
@@ -423,6 +423,98 @@ static int memblock_add_near_max_check(void)
return 0;
}

+/*
+ * A test that trying to add the 129th memory block.
+ * Expect to trigger memblock_double_array() to double the
+ * memblock.memory.max, find a new valid memory as
+ * memory.regions.
+ */
+static int memblock_add_many_check(void)
+{
+ int i;
+ void *orig_region;
+ struct region r = {
+ .base = SZ_16K,
+ .size = SZ_16K,
+ };
+ phys_addr_t new_memory_regions_size;
+ phys_addr_t base, size = SZ_64;
+ phys_addr_t gap_size = SZ_64;
+
+ PREFIX_PUSH();
+
+ reset_memblock_regions();
+ memblock_allow_resize();
+
+ dummy_physical_memory_init();
+ /*
+ * We allocated enough memory by using dummy_physical_memory_init(), and
+ * split it into small block. First we split a large enough memory block
+ * as the memory region which will be choosed by memblock_double_array().
+ */
+ base = PAGE_ALIGN(dummy_physical_memory_base());
+ new_memory_regions_size = PAGE_ALIGN(INIT_MEMBLOCK_REGIONS * 2 *
+ sizeof(struct memblock_region));
+ memblock_add(base, new_memory_regions_size);
+
+ /* This is the base of small memory block. */
+ base += new_memory_regions_size + gap_size;
+
+ orig_region = memblock.memory.regions;
+
+ for (i = 0; i < INIT_MEMBLOCK_REGIONS; i++) {
+ /*
+ * Add these small block to fulfill the memblock. We keep a
+ * gap between the nearby memory to avoid being merged.
+ */
+ memblock_add(base, size);
+ base += size + gap_size;
+
+ ASSERT_EQ(memblock.memory.cnt, i + 2);
+ ASSERT_EQ(memblock.memory.total_size, new_memory_regions_size +
+ (i + 1) * size);
+ }
+
+ /*
+ * At there, memblock_double_array() has been succeed, check if it
+ * update the memory.max.
+ */
+ ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
+
+ /* memblock_double_array() will reserve the memory it used. Check it. */
+ ASSERT_EQ(memblock.reserved.cnt, 1);
+ ASSERT_EQ(memblock.reserved.total_size, new_memory_regions_size);
+
+ /*
+ * Now memblock_double_array() works fine. Let's check after the
+ * double_array(), the memblock_add() still works as normal.
+ */
+ memblock_add(r.base, r.size);
+ ASSERT_EQ(memblock.memory.regions[0].base, r.base);
+ ASSERT_EQ(memblock.memory.regions[0].size, r.size);
+
+ ASSERT_EQ(memblock.memory.cnt, INIT_MEMBLOCK_REGIONS + 2);
+ ASSERT_EQ(memblock.memory.total_size, INIT_MEMBLOCK_REGIONS * size +
+ new_memory_regions_size +
+ r.size);
+ ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
+
+ dummy_physical_memory_cleanup();
+
+ /*
+ * The current memory.regions is occupying a range of memory that
+ * allocated from dummy_physical_memory_init(). After free the memory,
+ * we must not use it. So restore the origin memory region to make sure
+ * the tests can run as normal and not affected by the double array.
+ */
+ memblock.memory.regions = orig_region;
+ memblock.memory.cnt = INIT_MEMBLOCK_REGIONS;
+
+ test_pass_pop();
+
+ return 0;
+}
+
static int memblock_add_checks(void)
{
prefix_reset();
@@ -438,6 +530,7 @@ static int memblock_add_checks(void)
memblock_add_twice_check();
memblock_add_between_check();
memblock_add_near_max_check();
+ memblock_add_many_check();

prefix_pop();

diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c
index 3f795047bbe1..f43b6f414983 100644
--- a/tools/testing/memblock/tests/common.c
+++ b/tools/testing/memblock/tests/common.c
@@ -5,8 +5,6 @@
#include <linux/memory_hotplug.h>
#include <linux/build_bug.h>

-#define INIT_MEMBLOCK_REGIONS 128
-#define INIT_MEMBLOCK_RESERVED_REGIONS INIT_MEMBLOCK_REGIONS
#define PREFIXES_MAX 15
#define DELIM ": "
#define BASIS 10000
@@ -115,6 +113,11 @@ void dummy_physical_memory_cleanup(void)
free(memory_block.base);
}

+phys_addr_t dummy_physical_memory_base(void)
+{
+ return (phys_addr_t)memory_block.base;
+}
+
static void usage(const char *prog)
{
BUILD_BUG_ON(ARRAY_SIZE(help_opts) != ARRAY_SIZE(long_opts) - 1);
diff --git a/tools/testing/memblock/tests/common.h b/tools/testing/memblock/tests/common.h
index d6bbbe63bfc3..cc82b85151b6 100644
--- a/tools/testing/memblock/tests/common.h
+++ b/tools/testing/memblock/tests/common.h
@@ -10,9 +10,12 @@
#include <linux/printk.h>
#include <../selftests/kselftest.h>

-#define MEM_SIZE SZ_16K
+#define MEM_SIZE SZ_32K
#define NUMA_NODES 8

+#define INIT_MEMBLOCK_REGIONS 128
+#define INIT_MEMBLOCK_RESERVED_REGIONS INIT_MEMBLOCK_REGIONS
+
enum test_flags {
/* No special request. */
TEST_F_NONE = 0x0,
@@ -124,6 +127,7 @@ void setup_memblock(void);
void setup_numa_memblock(const unsigned int node_fracs[]);
void dummy_physical_memory_init(void);
void dummy_physical_memory_cleanup(void);
+phys_addr_t dummy_physical_memory_base(void);
void parse_args(int argc, char **argv);

void test_fail(void);
--
2.34.1