1/*
2 * Copyright (c) 2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Kevin Lim
29 */
30
31#ifndef __CPU_ACTIVITY_HH__
32#define __CPU_ACTIVITY_HH__
33
| 1/*
2 * Copyright (c) 2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Kevin Lim
29 */
30
31#ifndef __CPU_ACTIVITY_HH__
32#define __CPU_ACTIVITY_HH__
33
|
34#include "cpu/timebuf.hh"
| |
35#include "base/trace.hh"
| 34#include "base/trace.hh"
|
| 35#include "cpu/timebuf.hh"
|
36
37/**
38 * ActivityRecorder helper class that informs the CPU if it can switch
39 * over to being idle or not. It works by having a time buffer as
40 * long as any time buffer in the CPU, and the CPU and all of its
41 * stages inform the ActivityRecorder when they write to any time
42 * buffer. The ActivityRecorder marks a 1 in the "0" slot of the time
43 * buffer any time a stage writes to a time buffer, and it advances
44 * its time buffer at the same time as all other stages. The
45 * ActivityRecorder also records if a stage has activity to do next
46 * cycle. The recorder keeps a count of these two. Thus any time the
47 * count is non-zero, there is either communication still in flight,
48 * or activity that still must be done, meaning that the CPU can not
49 * idle. If count is zero, then the CPU can safely idle as it has no
50 * more outstanding work to do.
51 */
52class ActivityRecorder
53{
54 public:
55 ActivityRecorder(const std::string &name, int num_stages,
56 int longest_latency, int count);
57
58 /** Records that there is activity this cycle. */
59 void activity();
60
61 /** Advances the activity buffer, decrementing the activityCount
62 * if active communication just left the time buffer, and
63 * determining if there is no activity.
64 */
65 void advance();
66
67 /** Marks a stage as active. */
68 void activateStage(const int idx);
69
70 /** Deactivates a stage. */
71 void deactivateStage(const int idx);
72
73 /** Returns how many things are active within the recorder. */
74 int getActivityCount() { return activityCount; }
75
76 /** Sets the count to a starting value. Can be used to disable
77 * the idling option.
78 */
79 void setActivityCount(int count)
80 { activityCount = count; }
81
82 /** Returns if the CPU should be active. */
83 bool active() { return activityCount; }
84
85 /** Clears the time buffer and the activity count. */
86 void reset();
87
88 /** Debug function to dump the contents of the time buffer. */
89 void dump();
90
91 /** Debug function to ensure that the activity count matches the
92 * contents of the time buffer.
93 */
94 void validate();
95
96 private:
97 // provide name() for DPRINTF.
98 std::string _name;
99 const std::string &name() { return _name; }
100
101 /** Time buffer that tracks if any cycles has active communication
102 * in them. It should be as long as the longest communication
103 * latency in the system. Each time any time buffer is written,
104 * the activity buffer should also be written to. The
105 * activityBuffer is advanced along with all the other time
106 * buffers, so it should have a 1 somewhere in it only if there
107 * is active communication in a time buffer.
108 */
109 TimeBuffer<bool> activityBuffer;
110
111 /** Longest latency time buffer in the CPU. */
112 int longestLatency;
113
114 /** Tracks how many stages and cycles of time buffer have
115 * activity. Stages increment this count when they switch to
116 * active, and decrement it when they switch to
117 * inactive. Whenever a cycle that previously had no information
118 * is written in the time buffer, this is incremented. When a
119 * cycle that had information exits the time buffer due to age,
120 * this count is decremented. When the count is 0, there is no
121 * activity in the CPU, and it can be descheduled.
122 */
123 int activityCount;
124
125 /** Number of stages that can be marked as active or inactive. */
126 int numStages;
127
128 /** Records which stages are active/inactive. */
129 bool *stageActive;
130};
131
132#endif // __CPU_ACTIVITY_HH__
| 36
37/**
38 * ActivityRecorder helper class that informs the CPU if it can switch
39 * over to being idle or not. It works by having a time buffer as
40 * long as any time buffer in the CPU, and the CPU and all of its
41 * stages inform the ActivityRecorder when they write to any time
42 * buffer. The ActivityRecorder marks a 1 in the "0" slot of the time
43 * buffer any time a stage writes to a time buffer, and it advances
44 * its time buffer at the same time as all other stages. The
45 * ActivityRecorder also records if a stage has activity to do next
46 * cycle. The recorder keeps a count of these two. Thus any time the
47 * count is non-zero, there is either communication still in flight,
48 * or activity that still must be done, meaning that the CPU can not
49 * idle. If count is zero, then the CPU can safely idle as it has no
50 * more outstanding work to do.
51 */
52class ActivityRecorder
53{
54 public:
55 ActivityRecorder(const std::string &name, int num_stages,
56 int longest_latency, int count);
57
58 /** Records that there is activity this cycle. */
59 void activity();
60
61 /** Advances the activity buffer, decrementing the activityCount
62 * if active communication just left the time buffer, and
63 * determining if there is no activity.
64 */
65 void advance();
66
67 /** Marks a stage as active. */
68 void activateStage(const int idx);
69
70 /** Deactivates a stage. */
71 void deactivateStage(const int idx);
72
73 /** Returns how many things are active within the recorder. */
74 int getActivityCount() { return activityCount; }
75
76 /** Sets the count to a starting value. Can be used to disable
77 * the idling option.
78 */
79 void setActivityCount(int count)
80 { activityCount = count; }
81
82 /** Returns if the CPU should be active. */
83 bool active() { return activityCount; }
84
85 /** Clears the time buffer and the activity count. */
86 void reset();
87
88 /** Debug function to dump the contents of the time buffer. */
89 void dump();
90
91 /** Debug function to ensure that the activity count matches the
92 * contents of the time buffer.
93 */
94 void validate();
95
96 private:
97 // provide name() for DPRINTF.
98 std::string _name;
99 const std::string &name() { return _name; }
100
101 /** Time buffer that tracks if any cycles has active communication
102 * in them. It should be as long as the longest communication
103 * latency in the system. Each time any time buffer is written,
104 * the activity buffer should also be written to. The
105 * activityBuffer is advanced along with all the other time
106 * buffers, so it should have a 1 somewhere in it only if there
107 * is active communication in a time buffer.
108 */
109 TimeBuffer<bool> activityBuffer;
110
111 /** Longest latency time buffer in the CPU. */
112 int longestLatency;
113
114 /** Tracks how many stages and cycles of time buffer have
115 * activity. Stages increment this count when they switch to
116 * active, and decrement it when they switch to
117 * inactive. Whenever a cycle that previously had no information
118 * is written in the time buffer, this is incremented. When a
119 * cycle that had information exits the time buffer due to age,
120 * this count is decremented. When the count is 0, there is no
121 * activity in the CPU, and it can be descheduled.
122 */
123 int activityCount;
124
125 /** Number of stages that can be marked as active or inactive. */
126 int numStages;
127
128 /** Records which stages are active/inactive. */
129 bool *stageActive;
130};
131
132#endif // __CPU_ACTIVITY_HH__
|