[patch 020/166] mm: remove CONFIG_TRANSPARENT_HUGE_PAGECACHE

Andrew Morton
2020-04-07T03:04:38Z

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: mm: remove CONFIG_TRANSPARENT_HUGE_PAGECACHE

Commit e496cf3d7821 ("thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE")
notes that it should be reverted when the PowerPC problem was fixed. The
commit fixing the PowerPC problem (953c66c2b22a) did not revert the
commit; instead setting CONFIG_TRANSPARENT_HUGE_PAGECACHE to the same as
CONFIG_TRANSPARENT_HUGEPAGE. Checking with Kirill and Aneesh, this was an
oversight, so remove the Kconfig symbol and undo the work of commit
e496cf3d7821.

Link: http://lkml.kernel.org/r/20200318140253.6141-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

include/linux/shmem_fs.h | 10 +---------
mm/Kconfig | 6 +-----
mm/huge_memory.c | 2 +-
mm/khugepaged.c | 12 ++++--------
mm/memory.c | 5 ++---
mm/rmap.c | 2 +-
mm/shmem.c | 34 +++++++++++++++++-----------------
7 files changed, 27 insertions(+), 44 deletions(-)

--- a/include/linux/shmem_fs.h~mm-remove-config_transparent_huge_pagecache
+++ a/include/linux/shmem_fs.h
@@ -78,6 +78,7 @@ extern void shmem_truncate_range(struct
extern int shmem_unuse(unsigned int type, bool frontswap,
unsigned long *fs_pages_to_unuse);

+extern bool shmem_huge_enabled(struct vm_area_struct *vma);
extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
pgoff_t start, pgoff_t end);
@@ -114,15 +115,6 @@ static inline bool shmem_file(struct fil
extern bool shmem_charge(struct inode *inode, long pages);
extern void shmem_uncharge(struct inode *inode, long pages);

-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
-extern bool shmem_huge_enabled(struct vm_area_struct *vma);
-#else
-static inline bool shmem_huge_enabled(struct vm_area_struct *vma)
-{
- return false;
-}
-#endif
-
#ifdef CONFIG_SHMEM
extern int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
struct vm_area_struct *dst_vma,
--- a/mm/huge_memory.c~mm-remove-config_transparent_huge_pagecache
+++ a/mm/huge_memory.c
@@ -326,7 +326,7 @@ static struct attribute *hugepage_attr[]
&defrag_attr.attr,
&use_zero_page_attr.attr,
&hpage_pmd_size_attr.attr,
-#if defined(CONFIG_SHMEM) && defined(CONFIG_TRANSPARENT_HUGE_PAGECACHE)
+#ifdef CONFIG_SHMEM
&shmem_enabled_attr.attr,
#endif
#ifdef CONFIG_DEBUG_VM
--- a/mm/Kconfig~mm-remove-config_transparent_huge_pagecache
+++ a/mm/Kconfig
@@ -420,10 +420,6 @@ config THP_SWAP

For selection by architectures with reasonable THP sizes.

-config TRANSPARENT_HUGE_PAGECACHE
- def_bool y
- depends on TRANSPARENT_HUGEPAGE
-
#
# UP and nommu archs use km based percpu allocator
#
@@ -714,7 +710,7 @@ config GUP_GET_PTE_LOW_HIGH

config READ_ONLY_THP_FOR_FS
bool "Read-only THP for filesystems (EXPERIMENTAL)"
- depends on TRANSPARENT_HUGE_PAGECACHE && SHMEM
+ depends on TRANSPARENT_HUGEPAGE && SHMEM

help
Allow khugepaged to put read-only file-backed pages in THP.
--- a/mm/khugepaged.c~mm-remove-config_transparent_huge_pagecache
+++ a/mm/khugepaged.c
@@ -414,8 +414,6 @@ static bool hugepage_vma_check(struct vm
(IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
vma->vm_file &&
(vm_flags & VM_DENYWRITE))) {
- if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE))
- return false;
return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
HPAGE_PMD_NR);
}
@@ -1258,7 +1256,7 @@ static void collect_mm_slot(struct mm_sl
}
}

-#if defined(CONFIG_SHMEM) && defined(CONFIG_TRANSPARENT_HUGE_PAGECACHE)
+#ifdef CONFIG_SHMEM
/*
* Notify khugepaged that given addr of the mm is pte-mapped THP. Then
* khugepaged should try to collapse the page table.
@@ -1973,6 +1971,8 @@ skip:
if (khugepaged_scan.address < hstart)
khugepaged_scan.address = hstart;
VM_BUG_ON(khugepaged_scan.address & ~HPAGE_PMD_MASK);
+ if (shmem_file(vma->vm_file) && !shmem_huge_enabled(vma))
+ goto skip;

while (khugepaged_scan.address < hend) {
int ret;
@@ -1984,14 +1984,10 @@ skip:
khugepaged_scan.address + HPAGE_PMD_SIZE >
hend);
if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) {
- struct file *file;
+ struct file *file = get_file(vma->vm_file);
pgoff_t pgoff = linear_page_index(vma,
khugepaged_scan.address);

- if (shmem_file(vma->vm_file)
- && !shmem_huge_enabled(vma))
- goto skip;
- file = get_file(vma->vm_file);
up_read(&mm->mmap_sem);
ret = 1;
khugepaged_scan_file(mm, file, pgoff, hpage);
--- a/mm/memory.c~mm-remove-config_transparent_huge_pagecache
+++ a/mm/memory.c
@@ -3373,7 +3373,7 @@ map_pte:
return 0;
}

-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void deposit_prealloc_pte(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
@@ -3475,8 +3475,7 @@ vm_fault_t alloc_set_pte(struct vm_fault
pte_t entry;
vm_fault_t ret;

- if (pmd_none(*vmf->pmd) && PageTransCompound(page) &&
- IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) {
+ if (pmd_none(*vmf->pmd) && PageTransCompound(page)) {
/* THP on COW? */
VM_BUG_ON_PAGE(memcg, page);

--- a/mm/rmap.c~mm-remove-config_transparent_huge_pagecache
+++ a/mm/rmap.c
@@ -933,7 +933,7 @@ static bool page_mkclean_one(struct page
set_pte_at(vma->vm_mm, address, pte, entry);
ret = 1;
} else {
-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
pmd_t *pmd = pvmw.pmd;
pmd_t entry;

--- a/mm/shmem.c~mm-remove-config_transparent_huge_pagecache
+++ a/mm/shmem.c
@@ -410,7 +410,7 @@ static bool shmem_confirm_swap(struct ad
#define SHMEM_HUGE_DENY (-1)
#define SHMEM_HUGE_FORCE (-2)

-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/* ifdef here to avoid bloating shmem.o when not necessary */

static int shmem_huge __read_mostly;
@@ -580,7 +580,7 @@ static long shmem_unused_huge_count(stru
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
return READ_ONCE(sbinfo->shrinklist_len);
}
-#else /* !CONFIG_TRANSPARENT_HUGE_PAGECACHE */
+#else /* !CONFIG_TRANSPARENT_HUGEPAGE */

#define shmem_huge SHMEM_HUGE_DENY

@@ -589,11 +589,11 @@ static unsigned long shmem_unused_huge_s
{
return 0;
}
-#endif /* CONFIG_TRANSPARENT_HUGE_PAGECACHE */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

static inline bool is_huge_enabled(struct shmem_sb_info *sbinfo)
{
- if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) &&
+ if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
(shmem_huge == SHMEM_HUGE_FORCE || sbinfo->huge) &&
shmem_huge != SHMEM_HUGE_DENY)
return true;
@@ -1059,7 +1059,7 @@ static int shmem_setattr(struct dentry *
* Part of the huge page can be beyond i_size: subject
* to shrink under memory pressure.
*/
- if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) {
+ if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
spin_lock(&sbinfo->shrinklist_lock);
/*
* _careful to defend against unlocked access to
@@ -1510,7 +1510,7 @@ static struct page *shmem_alloc_and_acct
int nr;
int err = -ENOSPC;

- if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE))
+ if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
huge = false;
nr = huge ? HPAGE_PMD_NR : 1;

@@ -2093,7 +2093,7 @@ unsigned long shmem_get_unmapped_area(st
get_area = current->mm->get_unmapped_area;
addr = get_area(file, uaddr, len, pgoff, flags);

- if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE))
+ if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
return addr;
if (IS_ERR_VALUE(addr))
return addr;
@@ -2232,7 +2232,7 @@ static int shmem_mmap(struct file *file,

file_accessed(file);
vma->vm_ops = &shmem_vm_ops;
- if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) &&
+ if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) <
(vma->vm_end & HPAGE_PMD_MASK)) {
khugepaged_enter(vma, vma->vm_flags);
@@ -3459,7 +3459,7 @@ static int shmem_parse_one(struct fs_con
case Opt_huge:
ctx->huge = result.uint_32;
if (ctx->huge != SHMEM_HUGE_NEVER &&
- !(IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) &&
+ !(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
has_transparent_hugepage()))
goto unsupported_parameter;
ctx->seen |= SHMEM_SEEN_HUGE;
@@ -3605,7 +3605,7 @@ static int shmem_show_options(struct seq
if (!gid_eq(sbinfo->gid, GLOBAL_ROOT_GID))
seq_printf(seq, ",gid=%u",
from_kgid_munged(&init_user_ns, sbinfo->gid));
-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/* Rightly or wrongly, show huge mount option unmasked by shmem_huge */
if (sbinfo->huge)
seq_printf(seq, ",huge=%s", shmem_format_huge(sbinfo->huge));
@@ -3850,7 +3850,7 @@ static const struct super_operations shm
.evict_inode = shmem_evict_inode,
.drop_inode = generic_delete_inode,
.put_super = shmem_put_super,
-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
.nr_cached_objects = shmem_unused_huge_count,
.free_cached_objects = shmem_unused_huge_scan,
#endif
@@ -3912,7 +3912,7 @@ int __init shmem_init(void)
goto out1;
}

-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY)
SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge;
else
@@ -3928,7 +3928,7 @@ out2:
return error;
}

-#if defined(CONFIG_TRANSPARENT_HUGE_PAGECACHE) && defined(CONFIG_SYSFS)
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && defined(CONFIG_SYSFS)
static ssize_t shmem_enabled_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
@@ -3980,9 +3980,9 @@ static ssize_t shmem_enabled_store(struc

struct kobj_attribute shmem_enabled_attr =
__ATTR(shmem_enabled, 0644, shmem_enabled_show, shmem_enabled_store);
-#endif /* CONFIG_TRANSPARENT_HUGE_PAGECACHE && CONFIG_SYSFS */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE && CONFIG_SYSFS */

-#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
bool shmem_huge_enabled(struct vm_area_struct *vma)
{
struct inode *inode = file_inode(vma->vm_file);
@@ -4017,7 +4017,7 @@ bool shmem_huge_enabled(struct vm_area_s
return false;
}
}
-#endif /* CONFIG_TRANSPARENT_HUGE_PAGECACHE */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#else /* !CONFIG_SHMEM */

@@ -4186,7 +4186,7 @@ int shmem_zero_setup(struct vm_area_stru
vma->vm_file = file;
vma->vm_ops = &shmem_vm_ops;

- if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) &&
+ if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) <
(vma->vm_end & HPAGE_PMD_MASK)) {
khugepaged_enter(vma, vma->vm_flags);
_