[PATCH v4 04/15] mm: pgtable: add statistics for P4D level page table

[Qi Zheng]

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

Signed-off-by: Qi Zheng <zhengqi.a...@bytedance.com>
Originally-by: Peter Zijlstra (Intel) <pet...@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