mirror of https://github.com/schoebel/mars
154 lines
3.5 KiB
C
154 lines
3.5 KiB
C
// (c) 2012 Thomas Schoebel-Theuer / 1&1 Internet AG
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#ifndef MARS_LIB_TIMING_H
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#define MARS_LIB_TIMING_H
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#include "brick.h"
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#include <linux/sched.h>
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/* Simple infrastructure for timing of arbitrary operations and creation
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* of some simple histogram statistics.
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*/
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#define TIMING_MAX 24
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struct timing_stats {
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#ifdef CONFIG_MARS_DEBUG
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int tim_count[TIMING_MAX];
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#endif
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};
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#define _TIME_THIS(_stamp1, _stamp2, _CODE) \
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({ \
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(_stamp1) = cpu_clock(raw_smp_processor_id()); \
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\
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_CODE; \
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\
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(_stamp2) = cpu_clock(raw_smp_processor_id()); \
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(_stamp2) - (_stamp1); \
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})
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#define TIME_THIS(_CODE) \
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({ \
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unsigned long long _stamp1; \
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unsigned long long _stamp2; \
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_TIME_THIS(_stamp1, _stamp2, _CODE); \
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})
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#ifdef CONFIG_MARS_DEBUG
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#define _TIME_STATS(_timing, _stamp1, _stamp2, _CODE) \
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({ \
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unsigned long long _time; \
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unsigned long _tmp; \
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int _i; \
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\
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_time = _TIME_THIS(_stamp1, _stamp2, _CODE); \
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\
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_tmp = _time / 1000; /* convert to us */ \
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_i = 0; \
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while (_tmp > 0 && _i < TIMING_MAX - 1) { \
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_tmp >>= 1; \
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_i++; \
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} \
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(_timing)->tim_count[_i]++; \
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_time; \
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})
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#define TIME_STATS(_timing, _CODE) \
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({ \
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unsigned long long _stamp1; \
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unsigned long long _stamp2; \
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_TIME_STATS(_timing, _stamp1, _stamp2, _CODE); \
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})
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extern int report_timing(struct timing_stats *tim, char *str, int maxlen);
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#else // CONFIG_MARS_DEBUG
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#define _TIME_STATS(_timing, _stamp1, _stamp2, _CODE) \
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((void)_timing, (_stamp1) = (_stamp2) = cpu_clock(raw_smp_processor_id()), _CODE, 0)
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#define TIME_STATS(_timing, _CODE) \
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((void)_timing, _CODE, 0)
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#define report_timing(tim,str,maxlen) ((void)tim, 0)
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#endif // CONFIG_MARS_DEBUG
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/* A banning represents some overloaded resource.
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*
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* Whenever overload is detected, you should call banning_hit()
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* telling that the overload is assumed / estimated to continue
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* for some duration in time.
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*
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* ATTENTION! These operations are deliberately raceful.
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* They are meant to deliver _hints_ (e.g. for IO scheduling
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* decisions etc), not hard facts!
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*
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* If you need locking, just surround these operations
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* with locking by yourself.
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*/
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struct banning {
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long long ban_last_hit;
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// statistical
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int ban_renew_count;
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int ban_count;
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};
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extern inline
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bool banning_hit(struct banning *ban, long long duration)
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{
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long long now = cpu_clock(raw_smp_processor_id());
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bool hit = ban->ban_last_hit >= now;
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long long new_hit = now + duration;
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ban->ban_renew_count++;
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if (!ban->ban_last_hit || ban->ban_last_hit < new_hit) {
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ban->ban_last_hit = new_hit;
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ban->ban_count++;
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}
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return hit;
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}
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extern inline
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bool banning_is_hit(struct banning *ban)
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{
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long long now = cpu_clock(raw_smp_processor_id());
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return (ban->ban_last_hit && ban->ban_last_hit >= now);
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}
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extern inline
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void banning_reset(struct banning *ban)
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{
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ban->ban_last_hit = 0;
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}
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/* Threshold: trigger a banning whenever some latency threshold
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* is exceeded.
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*/
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struct threshold {
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struct banning *thr_ban;
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// tunables
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int thr_limit; // in us
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int thr_factor; // in %
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int thr_plus; // in us
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// statistical
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int thr_triggered;
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int thr_true_hit;
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};
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extern inline
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void threshold_check(struct threshold *thr, long long latency)
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{
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if (thr->thr_limit &&
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latency > (long long)thr->thr_limit * 1000) {
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thr->thr_triggered++;
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if (!banning_hit(thr->thr_ban, latency * thr->thr_factor / 100 + thr->thr_plus * 1000))
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thr->thr_true_hit++;
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}
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}
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#endif
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