Re: [PATCH v3 1/3] memblock test: Add test to memblock_add() 129th region
From: Huang, Shaoqin
Date: Sun Sep 18 2022 - 05:49:11 EST
On 9/18/2022 5:25 PM, Mike Rapoport wrote:
On Tue, Sep 13, 2022 at 02:41:30PM +0800, shaoqin.huang@xxxxxxxxx wrote:
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 | 96 ++++++++++++++++++++++++
tools/testing/memblock/tests/common.c | 7 +-
tools/testing/memblock/tests/common.h | 3 +
3 files changed, 104 insertions(+), 2 deletions(-)
diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
index a13a57ba0815..7120fd8e47b1 100644
--- a/tools/testing/memblock/tests/basic_api.c
+++ b/tools/testing/memblock/tests/basic_api.c
@@ -423,6 +423,101 @@ 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 = MEM_SIZE,
+ };
+ phys_addr_t new_memory_regions_size;
+ phys_addr_t base, size, block_size;
+
+ 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);
Why don't you simply increase MEM_SIZE, to say 1M?
This will make all the calculations here way simpler.
Ok. I will increase MEM_SIZE. That can clean the calculation.
+
+ /*
+ * For the left memory, we split them into small block and add them into
+ * memblock later.
+ */
+ base += new_memory_regions_size;
+ size = MEM_SIZE - new_memory_regions_size;
+ block_size = size / (INIT_MEMBLOCK_REGIONS * 2);
+
+ orig_region = memblock.memory.regions;
+
+ for (i = 0; i < INIT_MEMBLOCK_REGIONS; i++) {
+ /*
+ * Add these small block to fulfill the memblock. We keep an
+ * interval between the nearby memory to avoid being merged.
+ */
+ memblock_add(base + block_size * (2 * i + 1), block_size);
+
+ ASSERT_EQ(memblock.memory.cnt, i + 2);
+ ASSERT_EQ(memblock.memory.total_size, new_memory_regions_size +
+ (i + 1) * block_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 * block_size +
+ new_memory_regions_size +
+ MEM_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 +533,7 @@ 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 eec6901081af..2de6a2b6efd2 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 ": "
@@ -84,6 +82,11 @@ 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 78128e109a95..ba14dc989ae9 100644
--- a/tools/testing/memblock/tests/common.h
+++ b/tools/testing/memblock/tests/common.h
@@ -11,6 +11,8 @@
#include <../selftests/kselftest.h>
#define MEM_SIZE SZ_16K
+#define INIT_MEMBLOCK_REGIONS 128
+#define INIT_MEMBLOCK_RESERVED_REGIONS INIT_MEMBLOCK_REGIONS
enum test_flags {
/* No special request. */
@@ -104,6 +106,7 @@ void reset_memblock_attributes(void);
void setup_memblock(void);
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