mm/migrate: correct failure handling if !hugepage_migration_support()

[firefly-linux-kernel-4.4.55.git] / mm / util.c

diff --git a/mm/util.c b/mm/util.c
index f7bc2096071cb925bc0e46d83d8156d38179dd0f..a24aa22f2473690c1e2fa95514f778c6c0c616a7 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -390,7 +390,10 @@ struct address_space *page_mapping(struct page *page)
 {
        struct address_space *mapping = page->mapping;
 
-       VM_BUG_ON(PageSlab(page));
+       /* This happens if someone calls flush_dcache_page on slab page */
+       if (unlikely(PageSlab(page)))
+               return NULL;
+
        if (unlikely(PageSwapCache(page))) {
                swp_entry_t entry;
 
@@ -401,13 +404,45 @@ struct address_space *page_mapping(struct page *page)
        return mapping;
 }
 
+int overcommit_ratio_handler(struct ctl_table *table, int write,
+                            void __user *buffer, size_t *lenp,
+                            loff_t *ppos)
+{
+       int ret;
+
+       ret = proc_dointvec(table, write, buffer, lenp, ppos);
+       if (ret == 0 && write)
+               sysctl_overcommit_kbytes = 0;
+       return ret;
+}
+
+int overcommit_kbytes_handler(struct ctl_table *table, int write,
+                            void __user *buffer, size_t *lenp,
+                            loff_t *ppos)
+{
+       int ret;
+
+       ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
+       if (ret == 0 && write)
+               sysctl_overcommit_ratio = 0;
+       return ret;
+}
+
 /*
  * Committed memory limit enforced when OVERCOMMIT_NEVER policy is used
  */
 unsigned long vm_commit_limit(void)
 {
-       return ((totalram_pages - hugetlb_total_pages())
-               * sysctl_overcommit_ratio / 100) + total_swap_pages;
+       unsigned long allowed;
+
+       if (sysctl_overcommit_kbytes)
+               allowed = sysctl_overcommit_kbytes >> (PAGE_SHIFT - 10);
+       else
+               allowed = ((totalram_pages - hugetlb_total_pages())
+                          * sysctl_overcommit_ratio / 100);
+       allowed += total_swap_pages;
+
+       return allowed;
 }