[PATCH 33/33] mm: Remove pgtable_{pmd, pte}_page_{ctor, dtor}() wrappers

Vishal Moola (Oracle)
2023-04-17T20:56:15Z

These functions are no longer necessary. Remove them and cleanup
Documentation referencing them.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
Documentation/mm/split_page_table_lock.rst | 12 +++++------
.../zh_CN/mm/split_page_table_lock.rst | 14 ++++++-------
include/linux/mm.h | 20 -------------------
3 files changed, 13 insertions(+), 33 deletions(-)

diff --git a/Documentation/mm/split_page_table_lock.rst b/Documentation/mm/split_page_table_lock.rst
index 50ee0dfc95be..b3c612183135 100644
--- a/Documentation/mm/split_page_table_lock.rst
+++ b/Documentation/mm/split_page_table_lock.rst
@@ -53,7 +53,7 @@ Support of split page table lock by an architecture
===================================================

There's no need in special enabling of PTE split page table lock: everything
-required is done by pgtable_pte_page_ctor() and pgtable_pte_page_dtor(), which
+required is done by ptdesc_pte_ctor() and ptdesc_pte_dtor(), which
must be called on PTE table allocation / freeing.

Make sure the architecture doesn't use slab allocator for page table
@@ -63,8 +63,8 @@ This field shares storage with page->ptl.
PMD split lock only makes sense if you have more than two page table
levels.

-PMD split lock enabling requires pgtable_pmd_page_ctor() call on PMD table
-allocation and pgtable_pmd_page_dtor() on freeing.
+PMD split lock enabling requires ptdesc_pmd_ctor() call on PMD table
+allocation and ptdesc_pmd_dtor() on freeing.

Allocation usually happens in pmd_alloc_one(), freeing in pmd_free() and
pmd_free_tlb(), but make sure you cover all PMD table allocation / freeing
@@ -72,7 +72,7 @@ paths: i.e X86_PAE preallocate few PMDs on pgd_alloc().

With everything in place you can set CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK.

-NOTE: pgtable_pte_page_ctor() and pgtable_pmd_page_ctor() can fail -- it must
+NOTE: ptdesc_pte_ctor() and ptdesc_pmd_ctor() can fail -- it must
be handled properly.

page->ptl
@@ -92,7 +92,7 @@ trick:
split lock with enabled DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC, but costs
one more cache line for indirect access;

-The spinlock_t allocated in pgtable_pte_page_ctor() for PTE table and in
-pgtable_pmd_page_ctor() for PMD table.
+The spinlock_t allocated in ptdesc_pte_ctor() for PTE table and in
+ptdesc_pmd_ctor() for PMD table.

Please, never access page->ptl directly -- use appropriate helper.
diff --git a/Documentation/translations/zh_CN/mm/split_page_table_lock.rst b/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
index 4fb7aa666037..a3323eb9dc40 100644
--- a/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
+++ b/Documentation/translations/zh_CN/mm/split_page_table_lock.rst
@@ -56,16 +56,16 @@ Hugetlb特定的辅助函数:
架构对分页表锁的支持
====================

-没有必要特别启用PTE分页表锁：所有需要的东西都由pgtable_pte_page_ctor()
-和pgtable_pte_page_dtor()完成，它们必须在PTE表分配/释放时被调用。
+没有必要特别启用PTE分页表锁：所有需要的东西都由ptdesc_pte_ctor()
+和ptdesc_pte_dtor()完成，它们必须在PTE表分配/释放时被调用。

确保架构不使用slab分配器来分配页表：slab使用page->slab_cache来分配其页
面。这个区域与page->ptl共享存储。

PMD分页锁只有在你有两个以上的页表级别时才有意义。

-启用PMD分页锁需要在PMD表分配时调用pgtable_pmd_page_ctor()，在释放时调
-用pgtable_pmd_page_dtor()。
+启用PMD分页锁需要在PMD表分配时调用ptdesc_pmd_ctor()，在释放时调
+用ptdesc_pmd_dtor()。

分配通常发生在pmd_alloc_one()中，释放发生在pmd_free()和pmd_free_tlb()
中，但要确保覆盖所有的PMD表分配/释放路径：即X86_PAE在pgd_alloc()中预先
@@ -73,7 +73,7 @@ PMD分页锁只有在你有两个以上的页表级别时才有意义。

一切就绪后，你可以设置CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK。

-注意：pgtable_pte_page_ctor()和pgtable_pmd_page_ctor()可能失败--必
+注意：ptdesc_pte_ctor()和ptdesc_pmd_ctor()可能失败--必
须正确处理。

page->ptl
@@ -90,7 +90,7 @@ page->ptl用于访问分割页表锁，其中'page'是包含该表的页面struc
的指针并动态分配它。这允许在启用DEBUG_SPINLOCK或DEBUG_LOCK_ALLOC的
情况下使用分页锁，但由于间接访问而多花了一个缓存行。

-PTE表的spinlock_t分配在pgtable_pte_page_ctor()中，PMD表的spinlock_t
-分配在pgtable_pmd_page_ctor()中。
+PTE表的spinlock_t分配在ptdesc_pte_ctor()中，PMD表的spinlock_t
+分配在ptdesc_pmd_ctor()中。

请不要直接访问page->ptl - -使用适当的辅助函数。
diff --git a/include/linux/mm.h b/include/linux/mm.h
index cb136d2fdf74..e08638dc58cf 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2858,11 +2858,6 @@ static inline bool ptdesc_pte_ctor(struct ptdesc *ptdesc)
return true;
}

-static inline bool pgtable_pte_page_ctor(struct page *page)
-{
- return ptdesc_pte_ctor(page_ptdesc(page));
-}
-
static inline void ptdesc_pte_dtor(struct ptdesc *ptdesc)
{
struct folio *folio = ptdesc_folio(ptdesc);
@@ -2872,11 +2867,6 @@ static inline void ptdesc_pte_dtor(struct ptdesc *ptdesc)
lruvec_stat_sub_folio(folio, NR_PAGETABLE);
}

-static inline void pgtable_pte_page_dtor(struct page *page)
-{
- ptdesc_pte_dtor(page_ptdesc(page));
-}
-
#define pte_offset_map_lock(mm, pmd, address, ptlp) \
({ \
spinlock_t *__ptl = pte_lockptr(mm, pmd); \
@@ -2967,11 +2957,6 @@ static inline bool ptdesc_pmd_ctor(struct ptdesc *ptdesc)
return true;
}

-static inline bool pgtable_pmd_page_ctor(struct page *page)
-{
- return ptdesc_pmd_ctor(page_ptdesc(page));
-}
-
static inline void ptdesc_pmd_dtor(struct ptdesc *ptdesc)
{
struct folio *folio = ptdesc_folio(ptdesc);
@@ -2981,11 +2966,6 @@ static inline void ptdesc_pmd_dtor(struct ptdesc *ptdesc)
lruvec_stat_sub_folio(folio, NR_PAGETABLE);
}

-static inline void pgtable_pmd_page_dtor(struct page *page)
-{
- ptdesc_pmd_dtor(page_ptdesc(page));
-}
-
/*
* No scalability reason to split PUD locks yet, but follow the same pattern
* as the PMD locks to make it easier if we decide to. The VM should not be
--
2.39.2