Before this commit, split_page_count() and collapse_page_count() updated
direct_pages_count using PTRS_PER_PTE constant. However, these functions
should use PTRS_PER_PMD if 1G page is split into 2M pages and vice versa
because 2M direct pages are managed by PMD.
This commit fixes {split,collapse}_page_count() to use PTRS_PER_PMD in
such cases. The basic behavior of these functions are unchanged because
x86's 1G page split and collapse are currently only supported on 64-bit
environment where PTRS_PER_PTE and PTRS_PER_PMD are both 512.
Signed-off-by: Yohei Kojima <yohei.kojima@sony.com>
---
I'm sorry I forgot adding Signed-off-by line.
v1:
- Add Signed-off-by line
- https://lore.kernel.org/all/3d8bca84657d8b22a007a052258be1fb2a7c917d.1763531142.git.Yohei.Kojima@sony.com/
---
arch/x86/mm/pat/set_memory.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 970981893c9b..aa6fa4894edb 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -97,25 +97,29 @@ static void split_page_count(int level)
return;
direct_pages_count[level]--;
- if (system_state == SYSTEM_RUNNING) {
- if (level == PG_LEVEL_2M)
+ if (level == PG_LEVEL_2M) {
+ if (system_state == SYSTEM_RUNNING)
count_vm_event(DIRECT_MAP_LEVEL2_SPLIT);
- else if (level == PG_LEVEL_1G)
+ direct_pages_count[PG_LEVEL_4K] += PTRS_PER_PTE;
+ } else if (level == PG_LEVEL_1G) {
+ if (system_state == SYSTEM_RUNNING)
count_vm_event(DIRECT_MAP_LEVEL3_SPLIT);
+ direct_pages_count[PG_LEVEL_2M] += PTRS_PER_PMD;
}
- direct_pages_count[level - 1] += PTRS_PER_PTE;
}
static void collapse_page_count(int level)
{
direct_pages_count[level]++;
- if (system_state == SYSTEM_RUNNING) {
- if (level == PG_LEVEL_2M)
+ if (level == PG_LEVEL_2M) {
+ if (system_state == SYSTEM_RUNNING)
count_vm_event(DIRECT_MAP_LEVEL2_COLLAPSE);
- else if (level == PG_LEVEL_1G)
+ direct_pages_count[PG_LEVEL_4K] -= PTRS_PER_PTE;
+ } else if (level == PG_LEVEL_1G) {
+ if (system_state == SYSTEM_RUNNING)
count_vm_event(DIRECT_MAP_LEVEL3_COLLAPSE);
+ direct_pages_count[PG_LEVEL_2M] -= PTRS_PER_PMD;
}
- direct_pages_count[level - 1] -= PTRS_PER_PTE;
}
void arch_report_meminfo(struct seq_file *m)
--
2.43.0