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mm/memblock: remove empty dummy entry

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The dummy entry is introduced in the initial implementation of lmb in
commit 7c8c6b9776 ("powerpc: Merge lmb.c and make MM initialization
use it.").

As the comment says the empty dummy entry is to simplify the code.

	/* Create a dummy zero size LMB which will get coalesced away later.
         * This simplifies the lmb_add() code below...
         */

While current code is reimplemented by Tejun in commit 784656f9c6
("memblock: Reimplement memblock_add_region()"). This empty dummy entry
seems not benefit the code any more.

Let's remove it.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Paul Mackerras <paulus@ozlabs.org>
CC: Tejun Heo <tj@kernel.org>
CC: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/r/20240405015821.13411-1-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
This commit is contained in:
Wei Yang 2024-04-05 01:58:21 +00:00 committed by Mike Rapoport (IBM)
parent c3f38fa61a
commit 721f4a6526
3 changed files with 8 additions and 11 deletions
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7
mm/memblock.c
View File

@ -114,12 +114,10 @@ static struct memblock_region memblock_physmem_init_regions[INIT_PHYSMEM_REGIONS
struct memblock memblock __initdata_memblock = {
.memory.regions = memblock_memory_init_regions,
.memory.cnt = 1, /* empty dummy entry */
.memory.max = INIT_MEMBLOCK_MEMORY_REGIONS,
.memory.name = "memory",
.reserved.regions = memblock_reserved_init_regions,
.reserved.cnt = 1, /* empty dummy entry */
.reserved.max = INIT_MEMBLOCK_RESERVED_REGIONS,
.reserved.name = "reserved",
@ -130,7 +128,6 @@ struct memblock memblock __initdata_memblock = {
#ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
struct memblock_type physmem = {
.regions = memblock_physmem_init_regions,
.cnt = 1, /* empty dummy entry */
.max = INIT_PHYSMEM_REGIONS,
.name = "physmem",
};
@ -356,7 +353,6 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u
/* Special case for empty arrays */
if (type->cnt == 0) {
WARN_ON(type->total_size != 0);
type->cnt = 1;
type->regions[0].base = 0;
type->regions[0].size = 0;
type->regions[0].flags = 0;
@ -600,12 +596,13 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
/* special case for empty array */
if (type->regions[0].size == 0) {
WARN_ON(type->cnt != 1 || type->total_size);
WARN_ON(type->cnt != 0 || type->total_size);
type->regions[0].base = base;
type->regions[0].size = size;
type->regions[0].flags = flags;
memblock_set_region_node(&type->regions[0], nid);
type->total_size = size;
type->cnt = 1;
return 0;
}

8
tools/testing/memblock/tests/basic_api.c
View File

@ -15,12 +15,12 @@ static int memblock_initialization_check(void)
PREFIX_PUSH();
ASSERT_NE(memblock.memory.regions, NULL);
ASSERT_EQ(memblock.memory.cnt, 1);
ASSERT_EQ(memblock.memory.cnt, 0);
ASSERT_EQ(memblock.memory.max, EXPECTED_MEMBLOCK_REGIONS);
ASSERT_EQ(strcmp(memblock.memory.name, "memory"), 0);
ASSERT_NE(memblock.reserved.regions, NULL);
ASSERT_EQ(memblock.reserved.cnt, 1);
ASSERT_EQ(memblock.reserved.cnt, 0);
ASSERT_EQ(memblock.memory.max, EXPECTED_MEMBLOCK_REGIONS);
ASSERT_EQ(strcmp(memblock.reserved.name, "reserved"), 0);
@ -1295,7 +1295,7 @@ static int memblock_remove_only_region_check(void)
ASSERT_EQ(rgn->base, 0);
ASSERT_EQ(rgn->size, 0);
ASSERT_EQ(memblock.memory.cnt, 1);
ASSERT_EQ(memblock.memory.cnt, 0);
ASSERT_EQ(memblock.memory.total_size, 0);
test_pass_pop();
@ -1723,7 +1723,7 @@ static int memblock_free_only_region_check(void)
ASSERT_EQ(rgn->base, 0);
ASSERT_EQ(rgn->size, 0);
ASSERT_EQ(memblock.reserved.cnt, 1);
ASSERT_EQ(memblock.reserved.cnt, 0);
ASSERT_EQ(memblock.reserved.total_size, 0);
test_pass_pop();

4
tools/testing/memblock/tests/common.c
View File

@ -40,13 +40,13 @@ void reset_memblock_regions(void)
{
memset(memblock.memory.regions, 0,
memblock.memory.cnt * sizeof(struct memblock_region));
memblock.memory.cnt = 1;
memblock.memory.cnt = 0;
memblock.memory.max = INIT_MEMBLOCK_REGIONS;
memblock.memory.total_size = 0;
memset(memblock.reserved.regions, 0,
memblock.reserved.cnt * sizeof(struct memblock_region));
memblock.reserved.cnt = 1;
memblock.reserved.cnt = 0;
memblock.reserved.max = INIT_MEMBLOCK_RESERVED_REGIONS;
memblock.reserved.total_size = 0;
}