*hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj);
if (unlikely(!*hugepage_kobj)) {
- printk(KERN_ERR "hugepage: failed kobject create\n");
+ printk(KERN_ERR "hugepage: failed to create transparent hugepage kobject\n");
return -ENOMEM;
}
err = sysfs_create_group(*hugepage_kobj, &hugepage_attr_group);
if (err) {
- printk(KERN_ERR "hugepage: failed register hugeage group\n");
+ printk(KERN_ERR "hugepage: failed to register transparent hugepage group\n");
goto delete_obj;
}
err = sysfs_create_group(*hugepage_kobj, &khugepaged_attr_group);
if (err) {
- printk(KERN_ERR "hugepage: failed register hugeage group\n");
+ printk(KERN_ERR "hugepage: failed to register transparent hugepage group\n");
goto remove_hp_group;
}
if (__pmd_trans_huge_lock(pmd, vma) == 1) {
pmd_t entry;
entry = pmdp_get_and_clear(mm, addr, pmd);
- if (!prot_numa)
+ if (!prot_numa) {
entry = pmd_modify(entry, newprot);
- else {
+ BUG_ON(pmd_write(entry));
+ } else {
struct page *page = pmd_page(*pmd);
/* only check non-shared pages */
entry = pmd_mknuma(entry);
}
}
- BUG_ON(pmd_write(entry));
set_pmd_at(mm, addr, pmd, entry);
spin_unlock(&vma->vm_mm->page_table_lock);
ret = 1;
BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
BUG_ON(!PageAnon(page));
- anon_vma = page_lock_anon_vma_read(page);
+
+ /*
+ * The caller does not necessarily hold an mmap_sem that would prevent
+ * the anon_vma disappearing so we first we take a reference to it
+ * and then lock the anon_vma for write. This is similar to
+ * page_lock_anon_vma_read except the write lock is taken to serialise
+ * against parallel split or collapse operations.
+ */
+ anon_vma = page_get_anon_vma(page);
if (!anon_vma)
goto out;
+ anon_vma_lock_write(anon_vma);
+
ret = 0;
if (!PageCompound(page))
goto out_unlock;
BUG_ON(PageCompound(page));
out_unlock:
- page_unlock_anon_vma_read(anon_vma);
+ anon_vma_unlock(anon_vma);
+ put_anon_vma(anon_vma);
out:
return ret;
}