Commit b4ed71f5 authored by Mark Rutland's avatar Mark Rutland Committed by Linus Torvalds
Browse files

mm: treewide: clarify pgtable_page_{ctor,dtor}() naming 

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com


Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Reviewed-by: default avatarMike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cc22c800

Documentation/vm/split_page_table_lock.rst

+5 −5
Original line number Diff line number Diff line
@@ -54,9 +54,9 @@ Hugetlb-specific helpers: 
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_page_ctor() and pgtable_page_dtor(),

which must be called on PTE table allocation / freeing.

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

must be called on PTE table allocation / freeing.



Make sure the architecture doesn't use slab allocator for page table

allocation: slab uses page->slab_cache for its pages.
@@ -74,7 +74,7 @@ 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_page_ctor() and pgtable_pmd_page_ctor() can fail -- it must

NOTE: pgtable_pte_page_ctor() and pgtable_pmd_page_ctor() can fail -- it must

be handled properly.



page->ptl
@@ -94,7 +94,7 @@ 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_page_ctor() for PTE table and in

The spinlock_t allocated in pgtable_pte_page_ctor() for PTE table and in

pgtable_pmd_page_ctor() for PMD table.



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

arch/arc/include/asm/pgalloc.h

+2 −2
Original line number Diff line number Diff line
@@ -108,7 +108,7 @@ pte_alloc_one(struct mm_struct *mm) 
		return 0;

	memzero((void *)pte_pg, PTRS_PER_PTE * sizeof(pte_t));

	page = virt_to_page(pte_pg);

	if (!pgtable_page_ctor(page)) {

	if (!pgtable_pte_page_ctor(page)) {

		__free_page(page);

		return 0;

	}
@@ -123,7 +123,7 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) 


static inline void pte_free(struct mm_struct *mm, pgtable_t ptep)

{

	pgtable_page_dtor(virt_to_page(ptep));

	pgtable_pte_page_dtor(virt_to_page(ptep));

	free_pages((unsigned long)ptep, __get_order_pte());

}

arch/arm/include/asm/tlb.h

+1 −1
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ static inline void __tlb_remove_table(void *_table) 
static inline void

__pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr)

{

	pgtable_page_dtor(pte);

	pgtable_pte_page_dtor(pte);



#ifndef CONFIG_ARM_LPAE

	/*

arch/arm/mm/mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -731,7 +731,7 @@ static void *__init late_alloc(unsigned long sz) 
{

	void *ptr = (void *)__get_free_pages(GFP_PGTABLE_KERNEL, get_order(sz));



	if (!ptr || !pgtable_page_ctor(virt_to_page(ptr)))

	if (!ptr || !pgtable_pte_page_ctor(virt_to_page(ptr)))

		BUG();

	return ptr;

}

arch/arm64/include/asm/tlb.h

+1 −1
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ static inline void tlb_flush(struct mmu_gather *tlb) 
static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,

				  unsigned long addr)

{

	pgtable_page_dtor(pte);

	pgtable_pte_page_dtor(pte);

	tlb_remove_table(tlb, pte);

}

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