On Tue, 26 Jun 2012, Glauber Costa wrote:

quoted

quoted

@@ -416,6 +423,43 @@ static inline void sock_update_memcg(struct sock *sk)
  static inline void sock_release_memcg(struct sock *sk)
  {
  }
+
+#define mem_cgroup_kmem_on 0
+#define __mem_cgroup_new_kmem_page(a, b, c) false
+#define __mem_cgroup_free_kmem_page(a,b )
+#define __mem_cgroup_commit_kmem_page(a, b, c)
+#define is_kmem_tracked_alloc (false)
  #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+
+static __always_inline
+bool mem_cgroup_new_kmem_page(gfp_t gfp, void *handle, int order)
+{
+	if (!mem_cgroup_kmem_on)
+		return true;
+	if (!is_kmem_tracked_alloc)
+		return true;
+	if (!current->mm)
+		return true;
+	if (in_interrupt())
+		return true;

You can't test for current->mm in irq context, so you need to check for
in_interrupt() first.

Right, thanks.

quoted

Also, what prevents __mem_cgroup_new_kmem_page()
from being called for a kthread that has called use_mm() before
unuse_mm()?

Nothing, but I also don't see how to prevent that.

You can test for current->flags & PF_KTHREAD following the check for 
in_interrupt() and return true, it's what you were trying to do with the 
check for !current->mm.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>