ceph/src/spdk/dpdk/examples/performance-thread/common/lthread_timer.h

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2015 Intel Corporation
   3  */
   4
   5
   6 #ifndef LTHREAD_TIMER_H_
   7 #define LTHREAD_TIMER_H_
   8
   9 #ifdef __cplusplus
  10 extern "C" {
  11 #endif
  12
  13 #include "lthread_int.h"
  14 #include "lthread_sched.h"
  15
  16
  17 static inline uint64_t
  18 _ns_to_clks(uint64_t ns)
  19 {
  20         /*
  21          * clkns needs to be divided by 1E9 to get ns clocks. However,
  22          * dividing by this first would lose a lot of accuracy.
  23          * Dividing after a multiply by ns, could cause overflow of
  24          * uint64_t if ns is about 5 seconds [if we assume a max tsc
  25          * rate of 4GHz]. Therefore we first divide by 1E4, then
  26          * multiply and finally divide by 1E5. This allows ns to be
  27          * values many hours long, without overflow, while still keeping
  28          * reasonable accuracy.
  29          */
  30         uint64_t clkns = rte_get_tsc_hz() / 1e4;
  31
  32         clkns *= ns;
  33         clkns /= 1e5;
  34
  35         return clkns;
  36 }
  37
  38
  39 static inline void
  40 _timer_start(struct lthread *lt, uint64_t clks)
  41 {
  42         if (clks > 0) {
  43                 DIAG_EVENT(lt, LT_DIAG_LTHREAD_TMR_START, &lt->tim, clks);
  44                 rte_timer_init(&lt->tim);
  45                 rte_timer_reset(&lt->tim,
  46                                 clks,
  47                                 SINGLE,
  48                                 rte_lcore_id(),
  49                                 _sched_timer_cb,
  50                                 (void *)lt);
  51         }
  52 }
  53
  54
  55 static inline void
  56 _timer_stop(struct lthread *lt)
  57 {
  58         if (lt != NULL) {
  59                 DIAG_EVENT(lt, LT_DIAG_LTHREAD_TMR_DELETE, &lt->tim, 0);
  60                 rte_timer_stop(&lt->tim);
  61         }
  62 }
  63
  64 #ifdef __cplusplus
  65 }
  66 #endif
  67
  68 #endif /* LTHREAD_TIMER_H_ */