Re: [PATCH v2] memblock test: Add test to memblock_add() 129th region

["Huang, Shaoqin" <shaoqin.huang@xxxxxxxxx>]

On 8/2/2022 3:15 PM, Mike Rapoport wrote:
> On Mon, Aug 01, 2022 at 02:48:36PM +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 some valid memory, when
> > memblock_double_array() choose a new memory region from memory.regions,
> > it will always choose a valid memory region if we add all valid memory
> > region, so the 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>
> > ---
> > Changelog:
> > ----------
> > v2:
> >    - Use ASSERT_EQ() to replace assert().
> >    - Not to expose memory_block, and add a function get_memory_block_base() to
> >    get the memory_block.base.
> >    - Add two functions for common usage, and now it has been used by this patch
> >    to allocate many valid memory regions and free them at the end.
> >
> >   tools/testing/memblock/tests/basic_api.c | 54 ++++++++++++++++++++++++
> >   tools/testing/memblock/tests/common.c    | 38 +++++++++++++++--
> >   tools/testing/memblock/tests/common.h    |  6 +++
> >   3 files changed, 95 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
> > index 66f46f261e66..46948d5a975e 100644
> > --- a/tools/testing/memblock/tests/basic_api.c
> > +++ b/tools/testing/memblock/tests/basic_api.c
> > @@ -326,6 +326,59 @@ static int memblock_add_twice_check(void)
> >   	return 0;
> >   }
> >   
> > +static int memblock_add_many_check(void)
> > +{
> > +	void *base[INIT_MEMBLOCK_REGIONS + 1];
> > +	void *orig_region;
> > +	struct region r = {
> > +		.base = SZ_16K,
> > +		.size = MEM_SIZE,
> > +	};
> > +
> > +	PREFIX_PUSH();
> > +
> > +	reset_memblock_regions();
> > +	memblock_allow_resize();
> > +
> > +	dummy_physical_memory_many_init(base, INIT_MEMBLOCK_REGIONS);
>
> Why do we need this?

I want to memblock_add() 128 regions that every region has a valid 
"physical" memory. So it can make sure the memblock_double_array() 
success when add a 129-th region.

In the last patch, I didn't put this function here, I just 
memblock_add() 128 region at here. And after I think if we can 
encapsulate it to a function, later it can be used to init some valid 
memory regions into the memblock.

And if no others may be use this functions, the function is not needed.

> dummy_physical_memory_init() allocates the "physical" memory, so to trigger
> memblock_double_array() it's enough to memblock_add() 129 non-intersecting
> chunks in the range [memory_block.base, memory_block.base + MEM_SIZE].
> If MEM_SIZE of 16k won't be enough, it can be increased.

Yes. And now MEM_SIZE of 16k is enough, no need to increase it now.

> > +
> > +	orig_region = memblock.memory.regions;
> > +
> > +	/* This adds the 129 memory_region, and makes it double array. */
> > +	dummy_physical_memory_init();
> > +	append_memblock();
> > +	base[INIT_MEMBLOCK_REGIONS] = get_memory_block_base();
> > +
> > +	ASSERT_EQ(memblock.memory.cnt, INIT_MEMBLOCK_REGIONS + 1);
> > +	ASSERT_EQ(memblock.memory.total_size, (INIT_MEMBLOCK_REGIONS + 1) * MEM_SIZE);
> > +	ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
> > +
> > +	/* The base is very small, so it should be insert to the first region. */
> > +	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 + 2) * MEM_SIZE);
> > +	ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
> > +
> > +	/* Free these allocated memory. */
> > +	dummy_physical_memory_many_cleanup(base, INIT_MEMBLOCK_REGIONS + 1);
> > +
> > +	/*
> > +	 * 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();
> > @@ -339,6 +392,7 @@ static int memblock_add_checks(void)
> >   	memblock_add_overlap_bottom_check();
> >   	memblock_add_within_check();
> >   	memblock_add_twice_check();
> > +	memblock_add_many_check();
> >   
> >   	prefix_pop();
> >   
> > diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c
> > index e43b2676af81..960b3ce07696 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					": "
> >   
> > @@ -58,10 +56,20 @@ void reset_memblock_attributes(void)
> >   	memblock.current_limit	= MEMBLOCK_ALLOC_ANYWHERE;
> >   }
> >   
> > +void *get_memory_block_base(void)
> > +{
> > +	return memory_block.base;
> > +}
> > +
> > +void append_memblock(void)
> > +{
> > +	memblock_add((phys_addr_t)memory_block.base, MEM_SIZE);
> > +}
> > +
> >   void setup_memblock(void)
> >   {
> >   	reset_memblock_regions();
> > -	memblock_add((phys_addr_t)memory_block.base, MEM_SIZE);
> > +	append_memblock();
> >   }
> >   
> >   void dummy_physical_memory_init(void)
> > @@ -75,6 +83,30 @@ void dummy_physical_memory_cleanup(void)
> >   	free(memory_block.base);
> >   }
> >   
> > +void dummy_physical_memory_many_init(void *base[], int cnt)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < cnt; i++) {
> > +		dummy_physical_memory_init();
> > +		append_memblock();
> > +		base[i] = memory_block.base;
> > +
> > +		ASSERT_EQ(memblock.memory.cnt, i + 1);
> > +		ASSERT_EQ(memblock.memory.total_size, (i + 1) * MEM_SIZE);
> > +	}
> > +}
> > +
> > +void dummy_physical_memory_many_cleanup(void *base[], int cnt)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < cnt; i++) {
> > +		memory_block.base = base[i];
> > +		dummy_physical_memory_cleanup();
> > +	}
> > +}
> > +
> >   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 3e7f23d341d7..848900aa8db6 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
> >   
> >   /**
> >    * ASSERT_EQ():
> > @@ -68,8 +70,12 @@ struct region {
> >   void reset_memblock_regions(void);
> >   void reset_memblock_attributes(void);
> >   void setup_memblock(void);
> > +void append_memblock(void);
> > +void *get_memory_block_base(void);
> >   void dummy_physical_memory_init(void);
> >   void dummy_physical_memory_cleanup(void);
> > +void dummy_physical_memory_many_init(void *base[], int cnt);
> > +void dummy_physical_memory_many_cleanup(void *base[], int cnt);
> >   void parse_args(int argc, char **argv);
> >   
> >   void test_fail(void);
> > --
> > 2.30.2