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Update perf_counter.c

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Gabriel Wang 2024-12-06 11:45:14 +00:00 committed by GitHub
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commit 8895f2ba5e
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1 changed files with 7 additions and 18 deletions
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perf_counter.c
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@ -181,33 +181,22 @@ bool init_cycle_counter(bool bIsSysTickOccupied)
*/ */
__STATIC_INLINE int64_t check_systick(void) __STATIC_INLINE int64_t check_systick(void)
{ {
int64_t lLoad = perfc_port_get_system_timer_top() + 1;
int64_t lTemp = perfc_port_get_system_timer_elapsed(); int64_t lTemp = perfc_port_get_system_timer_elapsed();
/* Since we cannot stop counting temporarily, there are several /* Since we cannot stop counting temporarily, there are several
* conditions which we should take into consideration: * conditions which we should take into consideration:
* - Condition 1: when assigning nTemp with the register value (LOAD-VAL), * - Condition 1: when assigning nTemp with the register value (LOAD-VAL),
* the underflow didn't happen but when we check the PENDSTSET bit, * the underflow didn't happen but when we check the PENDSTSET bit,
* the underflow happens, for this condition, we should not * the underflow happens, for this condition, we should recall the
* do any compensation. When this happens, the (LOAD-nTemp) is * perfc_port_get_system_timer_elapsed().
* smaller than PERF_CNT_COMPENSATION_THRESHOLD (a small value) as
* long as LOAD is bigger than (or equals to) the
* PERF_CNT_COMPENSATION_THRESHOLD;
* - Condition 2: when assigning nTemp with the register value (LOAD-VAL),
* the VAL is zero and underflow happened and the PENDSTSET bit
* is set, for this condition, we should not do any compensation.
* When this happens, the (LOAD-nTemp) is equals to zero.
* - Condition 3: when assigning nTemp with the register value (LOAD-VAL),
* the underflow has already happened, hence the PENDSTSET
* is set, for this condition, we should compensate the return
* value. When this happens, the (LOAD-nTemp) is bigger than (or
* equals to) PERF_CNT_COMPENSATION_THRESHOLD.
* The following code implements an equivalent logic. * The following code implements an equivalent logic.
*/ */
if (perfc_port_is_system_timer_ovf_pending()){ if (perfc_port_is_system_timer_ovf_pending()){
//if ((lLoad - lTemp) >= PERF_CNT_COMPENSATION_THRESHOLD) { /* refresh the elapsed just in case the counter has just overflowed/underflowed
lTemp += lLoad; * after we called the perfc_port_get_system_timer_elapsed()
//} */
lTemp = perfc_port_get_system_timer_elapsed();
lTemp += perfc_port_get_system_timer_top() + 1;
} }
return lTemp; return lTemp;