atrace: add memory reclaim tracing

Add "memreclaim" to trace direct reclaim, shrink slab cycles, and
kswapd waking up and sleeping.

Change-Id: I4cfb313820a3a9aa5a9d07a39c42db41c24304a6
diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
index 9688cc6..fb40193 100644
--- a/cmds/atrace/atrace.cpp
+++ b/cmds/atrace/atrace.cpp
@@ -129,6 +129,12 @@
     { "workq",      "Kernel Workqueues", 0, {
         { REQ,      "/sys/kernel/debug/tracing/events/workqueue/enable" },
     } },
+    { "memreclaim", "Kernel Memory Reclaim", 0, {
+        { REQ,      "/sys/kernel/debug/tracing/events/vmscan/mm_vmscan_direct_reclaim_begin/enable" },
+        { REQ,      "/sys/kernel/debug/tracing/events/vmscan/mm_vmscan_direct_reclaim_end/enable" },
+        { REQ,      "/sys/kernel/debug/tracing/events/vmscan/mm_vmscan_kswapd_wake/enable" },
+        { REQ,      "/sys/kernel/debug/tracing/events/vmscan/mm_vmscan_kswapd_sleep/enable" },
+    } },
 };
 
 /* Command line options */