mm, oom: add description of struct oom_control
Describe the purpose of struct oom_control and what each member does.
Also make gfp_mask and order const since they are never manipulated or
passed to functions that discard the qualifier.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/oom.h b/include/linux/oom.h
index 8fb67b9..03e6257 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -12,11 +12,25 @@
struct mem_cgroup;
struct task_struct;
+/*
+ * Details of the page allocation that triggered the oom killer that are used to
+ * determine what should be killed.
+ */
struct oom_control {
+ /* Used to determine cpuset */
struct zonelist *zonelist;
- nodemask_t *nodemask;
- gfp_t gfp_mask;
- int order;
+
+ /* Used to determine mempolicy */
+ nodemask_t *nodemask;
+
+ /* Used to determine cpuset and node locality requirement */
+ const gfp_t gfp_mask;
+
+ /*
+ * order == -1 means the oom kill is required by sysrq, otherwise only
+ * for display purposes.
+ */
+ const int order;
};
/*