[PATCH v3 04/17] mm: pgtable: add statistics for P4D level page table

Qi Zheng
2024-12-23T09:43:54Z

Like other levels of page tables, add statistics for P4D level page table.

Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/riscv/include/asm/pgalloc.h | 6 +++++-
arch/x86/mm/pgtable.c | 3 +++
include/asm-generic/pgalloc.h | 2 ++
include/linux/mm.h | 16 ++++++++++++++++
4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
index 551d614d3369c..3466fbe2e508d 100644
--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -108,8 +108,12 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
unsigned long addr)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled) {
+ struct ptdesc *ptdesc = virt_to_ptdesc(p4d);
+
+ pagetable_p4d_dtor(ptdesc);
riscv_tlb_remove_ptdesc(tlb, virt_to_ptdesc(p4d));
+ }
}
#endif /* __PAGETABLE_PMD_FOLDED */

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 69a357b15974a..3d6e84da45b24 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -94,6 +94,9 @@ void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud)
#if CONFIG_PGTABLE_LEVELS > 4
void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d)
{
+ struct ptdesc *ptdesc = virt_to_ptdesc(p4d);
+
+ pagetable_p4d_dtor(ptdesc);
paravirt_release_p4d(__pa(p4d) >> PAGE_SHIFT);
paravirt_tlb_remove_table(tlb, virt_to_page(p4d));
}
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index 59131629ac9cc..bb482eeca0c3e 100644
--- a/include/asm-generic/pgalloc.h
+++ b/include/asm-generic/pgalloc.h
@@ -230,6 +230,7 @@ static inline p4d_t *__p4d_alloc_one_noprof(struct mm_struct *mm, unsigned long
if (!ptdesc)
return NULL;

+ pagetable_p4d_ctor(ptdesc);
return ptdesc_address(ptdesc);
}
#define __p4d_alloc_one(...) alloc_hooks(__p4d_alloc_one_noprof(__VA_ARGS__))
@@ -247,6 +248,7 @@ static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)
struct ptdesc *ptdesc = virt_to_ptdesc(p4d);

BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
+ pagetable_p4d_dtor(ptdesc);
pagetable_free(ptdesc);
}

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c49bc7b764535..5d82f42ddd5cc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3175,6 +3175,22 @@ static inline void pagetable_pud_dtor(struct ptdesc *ptdesc)
lruvec_stat_sub_folio(folio, NR_PAGETABLE);
}

+static inline void pagetable_p4d_ctor(struct ptdesc *ptdesc)
+{
+ struct folio *folio = ptdesc_folio(ptdesc);
+
+ __folio_set_pgtable(folio);
+ lruvec_stat_add_folio(folio, NR_PAGETABLE);
+}
+
+static inline void pagetable_p4d_dtor(struct ptdesc *ptdesc)
+{
+ struct folio *folio = ptdesc_folio(ptdesc);
+
+ __folio_clear_pgtable(folio);
+ lruvec_stat_sub_folio(folio, NR_PAGETABLE);
+}
+
extern void __init pagecache_init(void);
extern void free_initmem(void);

--
2.20.1