mm: thp: consolidate vma size check to transhuge_vma_suitable

There are couple of places that check whether the vma size is ok for THP
or whether address fits, they are open coded and duplicate, use
transhuge_vma_suitable() to do the job by passing in (vma->end -
HPAGE_PMD_SIZE).

Move vma size check into hugepage_vma_check().  This will make
khugepaged_enter() is as same as khugepaged_enter_vma().  There is just
one caller for khugepaged_enter(), replace it to khugepaged_enter_vma()
and remove khugepaged_enter().

Link: https://lkml.kernel.org/r/20220616174840.1202070-3-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zach 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: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 648cb3ce7099b46b4a4a7ed8204ed230715b1c97..8a5a8bfce0f54c757df5da55c6cdcffcf0f4445b 100644 (file)
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -116,6 +116,17 @@ extern struct kobj_attribute shmem_enabled_attr;
 
 extern unsigned long transparent_hugepage_flags;
 
+/*
+ * Do the below checks:
+ *   - For file vma, check if the linear page offset of vma is
+ *     HPAGE_PMD_NR aligned within the file.  The hugepage is
+ *     guaranteed to be hugepage-aligned within the file, but we must
+ *     check that the PMD-aligned addresses in the VMA map to
+ *     PMD-aligned offsets within the file, else the hugepage will
+ *     not be PMD-mappable.
+ *   - For all vmas, check if the haddr is in an aligned HPAGE_PMD_SIZE
+ *     area.
+ */
 static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
                unsigned long addr)
 {

diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h
index 392d34c3c59aaeee5c6db71bd27008a70ead5984..31ca8a7f78f4ffce73d7fb6369d3eb175a5a9eb3 100644 (file)
--- a/include/linux/khugepaged.h
+++ b/include/linux/khugepaged.h
@@ -51,16 +51,6 @@ static inline void khugepaged_exit(struct mm_struct *mm)
        if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
                __khugepaged_exit(mm);
 }
-
-static inline void khugepaged_enter(struct vm_area_struct *vma,
-                                  unsigned long vm_flags)
-{
-       if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
-           khugepaged_enabled()) {
-               if (hugepage_vma_check(vma, vm_flags))
-                       __khugepaged_enter(vma->vm_mm);
-       }
-}
 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
 {
@@ -68,10 +58,6 @@ static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm
 static inline void khugepaged_exit(struct mm_struct *mm)
 {
 }
-static inline void khugepaged_enter(struct vm_area_struct *vma,
-                                   unsigned long vm_flags)
-{
-}
 static inline void khugepaged_enter_vma(struct vm_area_struct *vma,
                                        unsigned long vm_flags)
 {

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index a563de8234c140c3f91083d9c6b7ddfd89278fd2..2751649aaf3385b4295aed23f62b13fbab42d49d 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -726,7 +726,7 @@ vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf)
                return VM_FAULT_FALLBACK;
        if (unlikely(anon_vma_prepare(vma)))
                return VM_FAULT_OOM;
-       khugepaged_enter(vma, vma->vm_flags);
+       khugepaged_enter_vma(vma, vma->vm_flags);
 
        if (!(vmf->flags & FAULT_FLAG_WRITE) &&
                        !mm_forbids_zeropage(vma->vm_mm) &&

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 3eec970a884d5016341a7191597f678df7372d99..c7e22135f1b561c4da3c97d6816192047c2a0c49 100644 (file)
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -443,8 +443,8 @@ bool hugepage_vma_check(struct vm_area_struct *vma,
        if (vma_is_dax(vma))
                return false;
 
-       if (vma->vm_file && !IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) -
-                               vma->vm_pgoff, HPAGE_PMD_NR))
+       /* 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. */
@@ -505,9 +505,7 @@ void khugepaged_enter_vma(struct vm_area_struct *vma,
                          unsigned long vm_flags)
 {
        if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
-           khugepaged_enabled() &&
-           (((vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK) <
-            (vma->vm_end & HPAGE_PMD_MASK))) {
+           khugepaged_enabled()) {
                if (hugepage_vma_check(vma, vm_flags))
                        __khugepaged_enter(vma->vm_mm);
        }
@@ -948,7 +946,6 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
                struct vm_area_struct **vmap)
 {
        struct vm_area_struct *vma;
-       unsigned long hstart, hend;
 
        if (unlikely(khugepaged_test_exit(mm)))
                return SCAN_ANY_PROCESS;
@@ -957,9 +954,7 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
        if (!vma)
                return SCAN_VMA_NULL;
 
-       hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
-       hend = vma->vm_end & HPAGE_PMD_MASK;
-       if (address < hstart || address + HPAGE_PMD_SIZE > hend)
+       if (!transhuge_vma_suitable(vma, address))
                return SCAN_ADDRESS_RANGE;
        if (!hugepage_vma_check(vma, vma->vm_flags))
                return SCAN_VMA_CHECK;
@@ -2135,10 +2130,8 @@ skip:
                        progress++;
                        continue;
                }
-               hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
-               hend = vma->vm_end & HPAGE_PMD_MASK;
-               if (hstart >= hend)
-                       goto skip;
+               hstart = round_up(vma->vm_start, HPAGE_PMD_SIZE);
+               hend = round_down(vma->vm_end, HPAGE_PMD_SIZE);
                if (khugepaged_scan.address > hend)
                        goto skip;
                if (khugepaged_scan.address < hstart)