1 files changed, 34 insertions, 36 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 5c2c355aa97f..52e725d4a866 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -148,57 +148,49 @@ static inline void free_task_struct(struct task_struct *tsk)
 }
 #endif
 
-void __weak arch_release_thread_info(struct thread_info *ti)
+void __weak arch_release_thread_stack(unsigned long *stack)
 {
 }
 
-#ifndef CONFIG_ARCH_THREAD_INFO_ALLOCATOR
+#ifndef CONFIG_ARCH_THREAD_STACK_ALLOCATOR
 
 /*
  * Allocate pages if THREAD_SIZE is >= PAGE_SIZE, otherwise use a
  * kmemcache based allocator.
  */
 # if THREAD_SIZE >= PAGE_SIZE
-static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
+static unsigned long *alloc_thread_stack_node(struct task_struct *tsk,
                                                   int node)
 {
-        struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP,
-                                                  THREAD_SIZE_ORDER);
-
-        if (page)
-                memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
-                                            1 << THREAD_SIZE_ORDER);
+        struct page *page = alloc_pages_node(node, THREADINFO_GFP,
+                                             THREAD_SIZE_ORDER);
 
         return page ? page_address(page) : NULL;
 }
 
-static inline void free_thread_info(struct thread_info *ti)
+static inline void free_thread_stack(unsigned long *stack)
 {
-        struct page *page = virt_to_page(ti);
-
-        memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
-                                    -(1 << THREAD_SIZE_ORDER));
-        __free_kmem_pages(page, THREAD_SIZE_ORDER);
+        __free_pages(virt_to_page(stack), THREAD_SIZE_ORDER);
 }
 # else
-static struct kmem_cache *thread_info_cache;
+static struct kmem_cache *thread_stack_cache;
 
-static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
+static unsigned long *alloc_thread_stack_node(struct task_struct *tsk,
                                                   int node)
 {
-        return kmem_cache_alloc_node(thread_info_cache, THREADINFO_GFP, node);
+        return kmem_cache_alloc_node(thread_stack_cache, THREADINFO_GFP, node);
 }
 
-static void free_thread_info(struct thread_info *ti)
+static void free_thread_stack(unsigned long *stack)
 {
-        kmem_cache_free(thread_info_cache, ti);
+        kmem_cache_free(thread_stack_cache, stack);
 }
 
-void thread_info_cache_init(void)
+void thread_stack_cache_init(void)
 {
-        thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
+        thread_stack_cache = kmem_cache_create("thread_stack", THREAD_SIZE,
                                               THREAD_SIZE, 0, NULL);
-        BUG_ON(thread_info_cache == NULL);
+        BUG_ON(thread_stack_cache == NULL);
 }
 # endif
 #endif
@@ -221,18 +213,24 @@ struct kmem_cache *vm_area_cachep;
 /* SLAB cache for mm_struct structures (tsk->mm) */
 static struct kmem_cache *mm_cachep;
 
-static void account_kernel_stack(struct thread_info *ti, int account)
+static void account_kernel_stack(unsigned long *stack, int account)
 {
-        struct zone *zone = page_zone(virt_to_page(ti));
+        /* All stack pages are in the same zone and belong to the same memcg. */
+        struct page *first_page = virt_to_page(stack);
+
+        mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB,
+                            THREAD_SIZE / 1024 * account);
 
-        mod_zone_page_state(zone, NR_KERNEL_STACK, account);
+        memcg_kmem_update_page_stat(
+                first_page, MEMCG_KERNEL_STACK_KB,
+                account * (THREAD_SIZE / 1024));
 }
 
 void free_task(struct task_struct *tsk)
 {
         account_kernel_stack(tsk->stack, -1);
-        arch_release_thread_info(tsk->stack);
-        free_thread_info(tsk->stack);
+        arch_release_thread_stack(tsk->stack);
+        free_thread_stack(tsk->stack);
         rt_mutex_debug_task_free(tsk);
         ftrace_graph_exit_task(tsk);
         put_seccomp_filter(tsk);
@@ -343,7 +341,7 @@ void set_task_stack_end_magic(struct task_struct *tsk)
 static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
 {
         struct task_struct *tsk;
-        struct thread_info *ti;
+        unsigned long *stack;
         int err;
 
         if (node == NUMA_NO_NODE)
@@ -352,15 +350,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
         if (!tsk)
                 return NULL;
 
-        ti = alloc_thread_info_node(tsk, node);
-        if (!ti)
+        stack = alloc_thread_stack_node(tsk, node);
+        if (!stack)
                 goto free_tsk;
 
         err = arch_dup_task_struct(tsk, orig);
         if (err)
-                goto free_ti;
+                goto free_stack;
 
-        tsk->stack = ti;
+        tsk->stack = stack;
 #ifdef CONFIG_SECCOMP
         /*
          * We must handle setting up seccomp filters once we're under
@@ -392,14 +390,14 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
         tsk->task_frag.page = NULL;
         tsk->wake_q.next = NULL;
 
-        account_kernel_stack(ti, 1);
+        account_kernel_stack(stack, 1);
 
         kcov_task_init(tsk);
 
         return tsk;
 
-free_ti:
-        free_thread_info(ti);
+free_stack:
+        free_thread_stack(stack);
 free_tsk:
         free_task_struct(tsk);
         return NULL;