mm/hugetlb: create hugetlb cgroup file in hugetlb_init

Build kernel with CONFIG_HUGETLBFS=y,CONFIG_HUGETLB_PAGE=y and
CONFIG_CGROUP_HUGETLB=y, then specify hugepagesz=xx boot option, system
will fail to boot.

This failure is caused by following code path:

  setup_hugepagesz
    hugetlb_add_hstate
      hugetlb_cgroup_file_init
        cgroup_add_cftypes
          kzalloc <--slab is *not available* yet

For this path, slab is not available yet, so memory allocated will be
failed, and cause WARN_ON() in hugetlb_cgroup_file_init().

So I move hugetlb_cgroup_file_init() into hugetlb_init().

[akpm@linux-foundation.org: tweak coding-style, remove pointless __init on inlined function]
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index d73878c694b3d43e85fc8b2d62f29107ed61d157..ce8217f7b5c224176178e95bcf5a76c75dd8dba6 100644 (file)
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h
@@ -62,7 +62,7 @@ extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
                                         struct page *page);
 extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
                                           struct hugetlb_cgroup *h_cg);
-extern int hugetlb_cgroup_file_init(int idx) __init;
+extern void hugetlb_cgroup_file_init(void) __init;
 extern void hugetlb_cgroup_migrate(struct page *oldhpage,
                                   struct page *newhpage);
 
@@ -111,9 +111,8 @@ hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
        return;
 }
 
-static inline int __init hugetlb_cgroup_file_init(int idx)
+static inline void hugetlb_cgroup_file_init(void)
 {
-       return 0;
 }
 
 static inline void hugetlb_cgroup_migrate(struct page *oldhpage,

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e5318c7793ae9f58bc7d21f0d2392d9d71b31a87..4f3ea0b1e57ce33bbf71bd1d3f41e04e11ae05dc 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1906,14 +1906,12 @@ static int __init hugetlb_init(void)
                default_hstate.max_huge_pages = default_hstate_max_huge_pages;
 
        hugetlb_init_hstates();
-
        gather_bootmem_prealloc();
-
        report_hugepages();
 
        hugetlb_sysfs_init();
-
        hugetlb_register_all_nodes();
+       hugetlb_cgroup_file_init();
 
        return 0;
 }
@@ -1943,13 +1941,6 @@ void __init hugetlb_add_hstate(unsigned order)
        h->next_nid_to_free = first_node(node_states[N_MEMORY]);
        snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
                                        huge_page_size(h)/1024);
-       /*
-        * Add cgroup control files only if the huge page consists
-        * of more than two normal pages. This is because we use
-        * page[2].lru.next for storing cgoup details.
-        */
-       if (order >= HUGETLB_CGROUP_MIN_ORDER)
-               hugetlb_cgroup_file_init(hugetlb_max_hstate - 1);
 
        parsed_hstate = h;
 }

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index b5bde7a5c017b19a266b9b2f25408e0713a4e967..9cea7de22ffbf351b8cc77eb40563543e38d59b7 100644 (file)
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -333,7 +333,7 @@ static char *mem_fmt(char *buf, int size, unsigned long hsize)
        return buf;
 }
 
-int __init hugetlb_cgroup_file_init(int idx)
+static void __init __hugetlb_cgroup_file_init(int idx)
 {
        char buf[32];
        struct cftype *cft;
@@ -375,7 +375,22 @@ int __init hugetlb_cgroup_file_init(int idx)
 
        WARN_ON(cgroup_add_cftypes(&hugetlb_subsys, h->cgroup_files));
 
-       return 0;
+       return;
+}
+
+void __init hugetlb_cgroup_file_init(void)
+{
+       struct hstate *h;
+
+       for_each_hstate(h) {
+               /*
+                * Add cgroup control files only if the huge page consists
+                * of more than two normal pages. This is because we use
+                * page[2].lru.next for storing cgroup details.
+                */
+               if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER)
+                       __hugetlb_cgroup_file_init(hstate_index(h));
+       }
 }
 
 /*