Commit 9a4bbd8d authored by Vishal Moola (Oracle)'s avatar Vishal Moola (Oracle) Committed by Andrew Morton
Browse files

mm: remove pgtable_{pmd, pte}_page_{ctor, dtor}() wrappers 

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

Link: https://lkml.kernel.org/r/20230807230513.102486-32-vishal.moola@gmail.com


Signed-off-by: default avatarVishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: default avatarMike Rapoport (IBM) <rppt@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent da9aefca

Documentation/mm/split_page_table_lock.rst

+6 −6
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ 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 pagetable_pte_ctor() and pagetable_pte_dtor(), which

must be called on PTE table allocation / freeing.



Make sure the architecture doesn't use slab allocator for page table
@@ -68,8 +68,8 @@ 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 pagetable_pmd_ctor() call on PMD table

allocation and pagetable_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
@@ -77,7 +77,7 @@ 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: pagetable_pte_ctor() and pagetable_pmd_ctor() can fail -- it must

be handled properly.



page->ptl
@@ -97,7 +97,7 @@ 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 pagetable_pte_ctor() for PTE table and in

pagetable_pmd_ctor() for PMD table.



Please, never access page->ptl directly -- use appropriate helper.

Documentation/translations/zh_CN/mm/split_page_table_lock.rst

+7 −7
Original line number Diff line number Diff line
@@ -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pagetable_pte_ctor()

和pagetable_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pagetable_pmd_ctor()，在释放时调

用pagetable_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：pagetable_pte_ctor()和pagetable_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pagetable_pte_ctor()中，PMD表的spinlock_t

分配在pagetable_pmd_ctor()中。



请不要直接访问page->ptl - -使用适当的辅助函数。

include/linux/mm.h

+0 −20
Original line number Diff line number Diff line
@@ -2898,11 +2898,6 @@ static inline bool pagetable_pte_ctor(struct ptdesc *ptdesc) 
	return true;

}



static inline bool pgtable_pte_page_ctor(struct page *page)

{

	return pagetable_pte_ctor(page_ptdesc(page));

}



static inline void pagetable_pte_dtor(struct ptdesc *ptdesc)

{

	struct folio *folio = ptdesc_folio(ptdesc);
@@ -2912,11 +2907,6 @@ static inline void pagetable_pte_dtor(struct ptdesc *ptdesc) 
	lruvec_stat_sub_folio(folio, NR_PAGETABLE);

}



static inline void pgtable_pte_page_dtor(struct page *page)

{

	pagetable_pte_dtor(page_ptdesc(page));

}



pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp);

static inline pte_t *pte_offset_map(pmd_t *pmd, unsigned long addr)

{
@@ -3023,11 +3013,6 @@ static inline bool pagetable_pmd_ctor(struct ptdesc *ptdesc) 
	return true;

}



static inline bool pgtable_pmd_page_ctor(struct page *page)

{

	return pagetable_pmd_ctor(page_ptdesc(page));

}



static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc)

{

	struct folio *folio = ptdesc_folio(ptdesc);
@@ -3037,11 +3022,6 @@ static inline void pagetable_pmd_dtor(struct ptdesc *ptdesc) 
	lruvec_stat_sub_folio(folio, NR_PAGETABLE);

}



static inline void pgtable_pmd_page_dtor(struct page *page)

{

	pagetable_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