Like split event counter, this patch add counter for merge event.
Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
---
arch/x86/mm/pat/set_memory.c | 19 +++++++++++++++++++
include/linux/vm_event_item.h | 2 ++
mm/vmstat.c | 2 ++
3 files changed, 23 insertions(+)
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index fea2c70ff37f..1be9aab42c79 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -105,6 +105,23 @@ static void split_page_count(int level)
direct_pages_count[level - 1] += PTRS_PER_PTE;
}
+static void merge_page_count(int level)
+{
+ if (direct_pages_count[level] < PTRS_PER_PTE) {
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+ direct_pages_count[level] -= PTRS_PER_PTE;
+ if (system_state == SYSTEM_RUNNING) {
+ if (level == PG_LEVEL_4K)
+ count_vm_event(DIRECT_MAP_LEVEL1_MERGE);
+ else if (level == PG_LEVEL_2M)
+ count_vm_event(DIRECT_MAP_LEVEL2_MERGE);
+ }
+ direct_pages_count[level + 1]++;
+}
+
void arch_report_meminfo(struct seq_file *m)
{
seq_printf(m, "DirectMap4k: %8lu kB\n",
@@ -875,6 +892,8 @@ static void merge_splitted_mapping(struct page *pgt, int level)
__ClearPageSplitpgt(pgt);
__free_page(pgt);
+
+ merge_page_count(level);
}
static pgprot_t pgprot_clear_protnone_bits(pgprot_t prot)
diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 404024486fa5..00a9a435af49 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -143,6 +143,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
#ifdef CONFIG_X86
DIRECT_MAP_LEVEL2_SPLIT,
DIRECT_MAP_LEVEL3_SPLIT,
+ DIRECT_MAP_LEVEL1_MERGE,
+ DIRECT_MAP_LEVEL2_MERGE,
#endif
NR_VM_EVENT_ITEMS
};
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 373d2730fcf2..1a4287a4d614 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1403,6 +1403,8 @@ const char * const vmstat_text[] = {
#ifdef CONFIG_X86
"direct_map_level2_splits",
"direct_map_level3_splits",
+ "direct_map_level1_merges",
+ "direct_map_level2_merges",
#endif
#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
};
--
2.37.1
