Commit 9fec5168 authored by Yang Shi's avatar Yang Shi Committed by Andrew Morton
Browse files

mm: thp: kill transparent_hugepage_active() 

The transparent_hugepage_active() was introduced to show THP eligibility
bit in smaps in proc, smaps is the only user.  But it actually does the
similar check as hugepage_vma_check() which is used by khugepaged.  We
definitely don't have to maintain two similar checks, so kill
transparent_hugepage_active().

This patch also fixed the wrong behavior for VM_NO_KHUGEPAGED vmas.

Also move hugepage_vma_check() to huge_memory.c and huge_mm.h since it
is not only for khugepaged anymore.

[akpm@linux-foundation.org: check vma->vm_mm, per Zach]
[akpm@linux-foundation.org: add comment to vdso check]
Link: https://lkml.kernel.org/r/20220616174840.1202070-5-shy828301@gmail.com


Signed-off-by: default avatarYang Shi <shy828301@gmail.com>
Reviewed-by: default avatarZach O'Keefe <zokeefe@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f707fa49

fs/proc/task_mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -863,7 +863,7 @@ static int show_smap(struct seq_file *m, void *v) 
	__show_smap(m, &mss, false);



	seq_printf(m, "THPeligible:    %d\n",

		   transparent_hugepage_active(vma));

		   hugepage_vma_check(vma, vma->vm_flags, true));



	if (arch_pkeys_enabled())

		seq_printf(m, "ProtectionKey:  %8u\n", vma_pkey(vma));

include/linux/huge_mm.h

+10 −6
Original line number Diff line number Diff line
@@ -202,7 +202,9 @@ static inline bool file_thp_enabled(struct vm_area_struct *vma) 
	       !inode_is_open_for_write(inode) && S_ISREG(inode->i_mode);

}



bool transparent_hugepage_active(struct vm_area_struct *vma);

bool hugepage_vma_check(struct vm_area_struct *vma,

			unsigned long vm_flags,

			bool smaps);



#define transparent_hugepage_use_zero_page()				\

	(transparent_hugepage_flags &					\
@@ -351,11 +353,6 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma) 
	return false;

}



static inline bool transparent_hugepage_active(struct vm_area_struct *vma)

{

	return false;

}



static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,

		unsigned long addr)

{
@@ -368,6 +365,13 @@ static inline bool transhuge_vma_enabled(struct vm_area_struct *vma, 
	return false;

}



static inline bool hugepage_vma_check(struct vm_area_struct *vma,

				       unsigned long vm_flags,

				       bool smaps)

{

	return false;

}



static inline void prep_transhuge_page(struct page *page) {}



#define transparent_hugepage_flags 0UL

include/linux/khugepaged.h

+0 −2
Original line number Diff line number Diff line
@@ -10,8 +10,6 @@ extern struct attribute_group khugepaged_attr_group; 
extern int khugepaged_init(void);

extern void khugepaged_destroy(void);

extern int start_stop_khugepaged(void);

extern bool hugepage_vma_check(struct vm_area_struct *vma,

			       unsigned long vm_flags);

extern void __khugepaged_enter(struct mm_struct *mm);

extern void __khugepaged_exit(struct mm_struct *mm);

extern void khugepaged_enter_vma(struct vm_area_struct *vma,

mm/huge_memory.c

+44 −9
Original line number Diff line number Diff line
@@ -69,21 +69,56 @@ static atomic_t huge_zero_refcount; 
struct page *huge_zero_page __read_mostly;

unsigned long huge_zero_pfn __read_mostly = ~0UL;



bool transparent_hugepage_active(struct vm_area_struct *vma)

bool hugepage_vma_check(struct vm_area_struct *vma,

			unsigned long vm_flags,

			bool smaps)

{

	/* The addr is used to check if the vma size fits */

	unsigned long addr = (vma->vm_end & HPAGE_PMD_MASK) - HPAGE_PMD_SIZE;

	if (!vma->vm_mm)		/* vdso */

		return false;



	if (!transhuge_vma_enabled(vma, vm_flags))

		return false;



	if (vm_flags & VM_NO_KHUGEPAGED)

		return false;



	if (!transhuge_vma_suitable(vma, addr))

	/* Don't run khugepaged against DAX vma */

	if (vma_is_dax(vma))

		return false;

	if (vma_is_anonymous(vma))

		return __transparent_hugepage_enabled(vma);

	if (vma_is_shmem(vma))



	/* Check alignment for file vma and size for both file and anon vma */

	if (!transhuge_vma_suitable(vma, (vma->vm_end - HPAGE_PMD_SIZE)))

		return false;



	/* Enabled via shmem mount options or sysfs settings. */

	if (shmem_file(vma->vm_file))

		return shmem_huge_enabled(vma);

	if (transhuge_vma_enabled(vma, vma->vm_flags) && file_thp_enabled(vma))



	if (!khugepaged_enabled())

		return false;



	/* THP settings require madvise. */

	if (!(vm_flags & VM_HUGEPAGE) && !khugepaged_always())

		return false;



	/* Only regular file is valid */

	if (file_thp_enabled(vma))

		return true;



	if (!vma_is_anonymous(vma))

		return false;



	if (vma_is_temporary_stack(vma))

		return false;



	/*

	 * THPeligible bit of smaps should show 1 for proper VMAs even

	 * though anon_vma is not initialized yet.

	 */

	if (!vma->anon_vma)

		return smaps;



	return true;

}



static bool get_huge_zero_page(void)

mm/khugepaged.c

+4 −44
Original line number Diff line number Diff line
@@ -430,46 +430,6 @@ static inline int khugepaged_test_exit(struct mm_struct *mm) 
	return atomic_read(&mm->mm_users) == 0;

}



bool hugepage_vma_check(struct vm_area_struct *vma,

			unsigned long vm_flags)

{

	if (!transhuge_vma_enabled(vma, vm_flags))

		return false;



	if (vm_flags & VM_NO_KHUGEPAGED)

		return false;



	/* Don't run khugepaged against DAX vma */

	if (vma_is_dax(vma))

		return false;



	/* Check alignment for file vma and size for both file and anon vma */

	if (!transhuge_vma_suitable(vma, (vma->vm_end - HPAGE_PMD_SIZE)))

		return false;



	/* Enabled via shmem mount options or sysfs settings. */

	if (shmem_file(vma->vm_file))

		return shmem_huge_enabled(vma);



	if (!khugepaged_enabled())

		return false;



	/* THP settings require madvise. */

	if (!(vm_flags & VM_HUGEPAGE) && !khugepaged_always())

		return false;



	/* Only regular file is valid */

	if (file_thp_enabled(vma))

		return true;



	if (!vma->anon_vma || !vma_is_anonymous(vma))

		return false;

	if (vma_is_temporary_stack(vma))

		return false;



	return true;

}



void __khugepaged_enter(struct mm_struct *mm)

{

	struct mm_slot *mm_slot;
@@ -506,7 +466,7 @@ void khugepaged_enter_vma(struct vm_area_struct *vma, 
{

	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&

	    khugepaged_enabled()) {

		if (hugepage_vma_check(vma, vm_flags))

		if (hugepage_vma_check(vma, vm_flags, false))

			__khugepaged_enter(vma->vm_mm);

	}

}
@@ -956,7 +916,7 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address, 


	if (!transhuge_vma_suitable(vma, address))

		return SCAN_ADDRESS_RANGE;

	if (!hugepage_vma_check(vma, vma->vm_flags))

	if (!hugepage_vma_check(vma, vma->vm_flags, false))

		return SCAN_VMA_CHECK;

	/*

	 * Anon VMA expected, the address may be unmapped then
@@ -1441,7 +1401,7 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr) 
	 * the valid THP. Add extra VM_HUGEPAGE so hugepage_vma_check()

	 * will not fail the vma for missing VM_HUGEPAGE

	 */

	if (!hugepage_vma_check(vma, vma->vm_flags | VM_HUGEPAGE))

	if (!hugepage_vma_check(vma, vma->vm_flags | VM_HUGEPAGE, false))

		return;



	/* Keep pmd pgtable for uffd-wp; see comment in retract_page_tables() */
@@ -2131,7 +2091,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, 
			progress++;

			break;

		}

		if (!hugepage_vma_check(vma, vma->vm_flags)) {

		if (!hugepage_vma_check(vma, vma->vm_flags, false)) {

skip:

			progress++;

			continue;