56 lines
1.1 KiB
C
56 lines
1.1 KiB
C
/*
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* Copyright 2013 Paweł Dziepak, pdziepak@quarnos.org.
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* Distributed under the terms of the MIT License.
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*/
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#ifndef _KERNEL_LOAD_TRACKING_H
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#define _KERNEL_LOAD_TRACKING_H
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const int32 kMaxLoad = 1000;
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const bigtime_t kLoadMeasureInterval = 50000;
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const bigtime_t kIntervalInaccuracy = kLoadMeasureInterval / 4;
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static int32
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compute_load(bigtime_t& measureTime, bigtime_t& measureActiveTime, int32& load)
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{
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bigtime_t now = system_time();
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if (measureTime == 0) {
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measureTime = now;
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return -1;
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}
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bigtime_t deltaTime = now - measureTime;
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if (deltaTime < kLoadMeasureInterval)
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return -1;
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int32 oldLoad = load;
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ASSERT(oldLoad >= 0 && oldLoad <= kMaxLoad);
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int32 newLoad = measureActiveTime * kMaxLoad;
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newLoad /= max_c(deltaTime, 1);
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newLoad = max_c(min_c(newLoad, kMaxLoad), 0);
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measureActiveTime = 0;
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measureTime = now;
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deltaTime += kIntervalInaccuracy;
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int n = deltaTime / kLoadMeasureInterval;
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ASSERT(n > 0);
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if (n > 10)
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load = newLoad;
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else {
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newLoad *= (1 << n) - 1;
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load = (load + newLoad) / (1 << n);
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ASSERT(load >= 0 && load <= kMaxLoad);
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}
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return oldLoad;
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}
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#endif // _KERNEL_LOAD_TRACKING_H
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