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authorRik van Riel <riel@surriel.com>2021-02-25 17:16:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-26 09:40:59 -0800
commitcd89fb06509903f942a0ffe97ffa63034671ed0c (patch)
treea5c530688dfd1109937e3019bd038577dcbeda6b
parent78cc8cdc54008f54b79711fc027afc3564588a04 (diff)
downloadlinux-leds-cd89fb06509903f942a0ffe97ffa63034671ed0c.tar.gz
mm,thp,shmem: make khugepaged obey tmpfs mount flags
Currently if thp enabled=[madvise], mounting a tmpfs filesystem with huge=always and mmapping files from that tmpfs does not result in khugepaged collapsing those mappings, despite the mount flag indicating that it should. Fix that by breaking up the blocks of tests in hugepage_vma_check a little bit, and testing things in the correct order. Link: https://lkml.kernel.org/r/20201124194925.623931-4-riel@surriel.com Fixes: c2231020ea7b ("mm: thp: register mm for khugepaged when merging vma for shmem") Signed-off-by: Rik van Riel <riel@surriel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xu Yu <xuyu@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/khugepaged.h2
-rw-r--r--mm/khugepaged.c22
2 files changed, 18 insertions, 6 deletions
diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h
index c941b73773216f..2fcc01891b474f 100644
--- a/include/linux/khugepaged.h
+++ b/include/linux/khugepaged.h
@@ -3,6 +3,7 @@
#define _LINUX_KHUGEPAGED_H
#include <linux/sched/coredump.h> /* MMF_VM_HUGEPAGE */
+#include <linux/shmem_fs.h>
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -57,6 +58,7 @@ static inline int khugepaged_enter(struct vm_area_struct *vma,
{
if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))
if ((khugepaged_always() ||
+ (shmem_file(vma->vm_file) && shmem_huge_enabled(vma)) ||
(khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) &&
!(vm_flags & VM_NOHUGEPAGE) &&
!test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 75e246f680f4f0..a7d6cb912b051b 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -442,18 +442,28 @@ static inline int khugepaged_test_exit(struct mm_struct *mm)
static bool hugepage_vma_check(struct vm_area_struct *vma,
unsigned long vm_flags)
{
- if ((!(vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
- (vm_flags & VM_NOHUGEPAGE) ||
+ /* Explicitly disabled through madvise. */
+ if ((vm_flags & VM_NOHUGEPAGE) ||
test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
return false;
- if (shmem_file(vma->vm_file) ||
- (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
- vma->vm_file &&
- (vm_flags & VM_DENYWRITE))) {
+ /* Enabled via shmem mount options or sysfs settings. */
+ if (shmem_file(vma->vm_file) && shmem_huge_enabled(vma)) {
return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
HPAGE_PMD_NR);
}
+
+ /* THP settings require madvise. */
+ if (!(vm_flags & VM_HUGEPAGE) && !khugepaged_always())
+ return false;
+
+ /* Read-only file mappings need to be aligned for THP to work. */
+ if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && vma->vm_file &&
+ (vm_flags & VM_DENYWRITE)) {
+ return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff,
+ HPAGE_PMD_NR);
+ }
+
if (!vma->anon_vma || vma->vm_ops)
return false;
if (vma_is_temporary_stack(vma))