lowmemorykiller: trace kill events.

Allows for capturing lmk kill events and their rationale. Change-Id: Ibe215db5bb9806fc550c72c0b9832c85cbd56bf6 Signed-off-by: Martijn Coenen <[email protected]>
yuweiyuan8 · Sep 6, 2016 · 3c9ebc1 · 3c9ebc1
1 parent cb0b3a4
commit 3c9ebc1
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Showing 2 changed files with 50 additions and 3 deletions.
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
@@ -41,6 +41,9 @@
 #include <linux/rcupdate.h>
 #include <linux/notifier.h>
 
+#define CREATE_TRACE_POINTS
+#include "trace/lowmemorykiller.h"
+
 static uint32_t lowmem_debug_level = 1;
 static short lowmem_adj[6] = {
 	0,
@@ -190,6 +193,10 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
 			     p->comm, p->pid, oom_score_adj, tasksize);
 	}
 	if (selected) {
+		long cache_size = other_file * (long)(PAGE_SIZE / 1024);
+		long cache_limit = minfree * (long)(PAGE_SIZE / 1024);
+		long free = other_free * (long)(PAGE_SIZE / 1024);
+		trace_lowmemory_kill(selected, cache_size, cache_limit, free);
 		lowmem_print(1, "Killing '%s' (%d), adj %hd,\n" \
 				"   to free %ldkB on behalf of '%s' (%d) because\n" \
 				"   cache %ldkB is below limit %ldkB for oom_score_adj %hd\n" \
@@ -198,10 +205,9 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
 			     selected_oom_score_adj,
 			     selected_tasksize * (long)(PAGE_SIZE / 1024),
 			     current->comm, current->pid,
-			     other_file * (long)(PAGE_SIZE / 1024),
-			     minfree * (long)(PAGE_SIZE / 1024),
+			     cache_size, cache_limit,
 			     min_score_adj,
-			     other_free * (long)(PAGE_SIZE / 1024));
+			     free);
 		lowmem_deathpending_timeout = jiffies + HZ;
 		send_sig(SIGKILL, selected, 0);
 		set_tsk_thread_flag(selected, TIF_MEMDIE);

diff --git a/drivers/staging/android/trace/lowmemorykiller.h b/drivers/staging/android/trace/lowmemorykiller.h
@@ -0,0 +1,41 @@
+#undef TRACE_SYSTEM
+#define TRACE_INCLUDE_PATH ../../drivers/staging/android/trace
+#define TRACE_SYSTEM lowmemorykiller
+
+#if !defined(_TRACE_LOWMEMORYKILLER_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_LOWMEMORYKILLER_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(lowmemory_kill,
+	TP_PROTO(struct task_struct *killed_task, long cache_size, \
+		 long cache_limit, long free),
+
+	TP_ARGS(killed_task, cache_size, cache_limit, free),
+
+	TP_STRUCT__entry(
+			__array(char, comm, TASK_COMM_LEN)
+			__field(pid_t, pid)
+			__field(long, pagecache_size)
+			__field(long, pagecache_limit)
+			__field(long, free)
+	),
+
+	TP_fast_assign(
+			memcpy(__entry->comm, killed_task->comm, TASK_COMM_LEN);
+			__entry->pid = killed_task->pid;
+			__entry->pagecache_size = cache_size;
+			__entry->pagecache_limit = cache_limit;
+			__entry->free = free;
+	),
+
+	TP_printk("%s (%d), page cache %ldkB (limit %ldkB), free %ldKb",
+		__entry->comm, __entry->pid, __entry->pagecache_size,
+		__entry->pagecache_limit, __entry->free)
+);
+
+
+#endif /* if !defined(_TRACE_LOWMEMORYKILLER_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>