1
2#ifndef __CPU_ACTIVITY_HH__
3#define __CPU_ACTIVITY_HH__
4
5#include "base/timebuf.hh"
6#include "base/trace.hh"
7
8class ActivityRecorder {
9 public:
10 ActivityRecorder(int num_stages, int longest_latency, int count);
11
12 /** Records that there is activity this cycle. */
13 void activity();
14 /** Advances the activity buffer, decrementing the activityCount if active
15 * communication just left the time buffer, and descheduling the CPU if
16 * there is no activity.
17 */
18 void advance();
19 /** Marks a stage as active. */
20 void activateStage(const int idx);
21 /** Deactivates a stage. */
22 void deactivateStage(const int idx);
23
24 int getActivityCount() { return activityCount; }
25
26 void setActivityCount(int count)
27 { activityCount = count; }
28
29 bool active() { return activityCount; }
30
31 void reset();
32
33 void dump();
34
35 void validate();
36
37 private:
38 /** Time buffer that tracks if any cycles has active communication
39 * in them. It should be as long as the longest communication
40 * latency in the system. Each time any time buffer is written,
41 * the activity buffer should also be written to. The
42 * activityBuffer is advanced along with all the other time
43 * buffers, so it should have a 1 somewhere in it only if there
44 * is active communication in a time buffer.
45 */
46 TimeBuffer<bool> activityBuffer;
47
48 int longestLatency;
49
50 /** Tracks how many stages and cycles of time buffer have
51 * activity. Stages increment this count when they switch to
52 * active, and decrement it when they switch to
53 * inactive. Whenever a cycle that previously had no information
54 * is written in the time buffer, this is incremented. When a
55 * cycle that had information exits the time buffer due to age,
56 * this count is decremented. When the count is 0, there is no
57 * activity in the CPU, and it can be descheduled.
58 */
59 int activityCount;
60
61 int numStages;
62
63 /** Records which stages are active/inactive. */
64 bool *stageActive;
65};
66
67#endif // __CPU_ACTIVITY_HH__