hugetlb: use same fault hash key for shared and private mappings

[mirror_ubuntu-bionic-kernel.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e3f672369f52c5e4432822a8956f61aad1bb3463..8255949949e39c6fbfb521c674e0f186e8ebb5b1 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3734,8 +3734,7 @@ retry:
                         * handling userfault.  Reacquire after handling
                         * fault to make calling code simpler.
                         */
-                       hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping,
-                                                       idx, address);
+                       hash = hugetlb_fault_mutex_hash(h, mapping, idx, address);
                        mutex_unlock(&hugetlb_fault_mutex_table[hash]);
                        ret = handle_userfault(&vmf, VM_UFFD_MISSING);
                        mutex_lock(&hugetlb_fault_mutex_table[hash]);
@@ -3847,21 +3846,14 @@ backout_unlocked:
 }
 
 #ifdef CONFIG_SMP
-u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
-                           struct vm_area_struct *vma,
-                           struct address_space *mapping,
+u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
                            pgoff_t idx, unsigned long address)
 {
        unsigned long key[2];
        u32 hash;
 
-       if (vma->vm_flags & VM_SHARED) {
-               key[0] = (unsigned long) mapping;
-               key[1] = idx;
-       } else {
-               key[0] = (unsigned long) mm;
-               key[1] = address >> huge_page_shift(h);
-       }
+       key[0] = (unsigned long) mapping;
+       key[1] = idx;
 
        hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
 
@@ -3872,9 +3864,7 @@ u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
  * For uniprocesor systems we always use a single mutex, so just
  * return 0 and avoid the hashing overhead.
  */
-u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
-                           struct vm_area_struct *vma,
-                           struct address_space *mapping,
+u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
                            pgoff_t idx, unsigned long address)
 {
        return 0;
@@ -3920,7 +3910,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
         * get spurious allocation failures if two CPUs race to instantiate
         * the same page in the page cache.
         */
-       hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping, idx, address);
+       hash = hugetlb_fault_mutex_hash(h, mapping, idx, address);
        mutex_lock(&hugetlb_fault_mutex_table[hash]);
 
        entry = huge_ptep_get(ptep);