2 * This file is part of the GROMACS molecular simulation package.
4 * Copyright (c) 2013, The GROMACS development team.
5 * Copyright (c) 2013,2014, by the GROMACS development team, led by
6 * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
7 * and including many others, as listed in the AUTHORS file in the
8 * top-level source directory and at http://www.gromacs.org.
10 * GROMACS is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public License
12 * as published by the Free Software Foundation; either version 2.1
13 * of the License, or (at your option) any later version.
15 * GROMACS is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with GROMACS; if not, see
22 * http://www.gnu.org/licenses, or write to the Free Software Foundation,
23 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 * If you want to redistribute modifications to GROMACS, please
26 * consider that scientific software is very special. Version
27 * control is crucial - bugs must be traceable. We will be happy to
28 * consider code for inclusion in the official distribution, but
29 * derived work must not be called official GROMACS. Details are found
30 * in the README & COPYING files - if they are missing, get the
31 * official version at http://www.gromacs.org.
33 * To help us fund GROMACS development, we humbly ask that you cite
34 * the research papers on the package. Check out http://www.gromacs.org.
36 #include "gromacs/timing/walltime_accounting.h"
46 #ifdef HAVE_SYS_TIME_H
50 #include "gromacs/utility/basedefinitions.h"
51 #include "gromacs/utility/smalloc.h"
53 /* TODO in future: convert gmx_walltime_accounting to a class,
54 * resolve who should have responsibility for recording the number of
55 * steps done, consider whether parts of finish_time, print_perf,
56 * wallcycle_print belong in this module.
58 * If/when any kind of task parallelism is implemented (even OpenMP
59 * regions simultaneously assigned to different tasks), consider
60 * whether this data structure (and/or cycle counters) should be
61 * maintained on a per-OpenMP-thread basis. */
63 /*! \brief Manages caching wall-clock time measurements for
65 typedef struct gmx_walltime_accounting {
66 //! Seconds since the epoch recorded at the start of the simulation
67 double start_time_stamp;
68 //! Seconds since the epoch recorded at the start of the simulation for this thread
69 double start_time_stamp_per_thread;
70 //! Total seconds elapsed over the simulation
72 //! Total seconds elapsed over the simulation running this thread
73 double elapsed_time_over_all_threads;
74 /*! \brief Number of OpenMP threads that will be launched by this
77 * This is used to scale elapsed_time_over_all_threads so
78 * that any combination of real MPI, thread MPI and OpenMP (even
79 * mdrun -ntomp_pme) processes/threads would (when run at maximum
80 * efficiency) return values such that the sum of
81 * elapsed_time_over_all_threads over all threads was constant
82 * with respect to parallelism implementation. */
84 //! Set by integrators to report the amount of work they did
85 gmx_int64_t nsteps_done;
86 } t_gmx_walltime_accounting;
88 /*! \brief Calls system timing routines (e.g. clock_gettime) to get
89 * the (fractional) number of seconds elapsed since the epoch when
90 * this thread was executing.
92 * This can be used to measure system load. This can be unreliable if
93 * threads migrate between sockets. If thread-specific timers are not
94 * supported by the OS (e.g. if the OS is not POSIX-compliant), this
95 * function is implemented by gmx_gettime. */
96 static double gmx_gettime_per_thread();
98 // TODO In principle, all this should get protected by checks that
99 // walltime_accounting is not null. In practice, that NULL condition
100 // does not happen, and future refactoring will likely enforce it by
101 // having the gmx_walltime_accounting_t object be owned by the runner
102 // object. When these become member functions, existence will be
105 gmx_walltime_accounting_t
106 walltime_accounting_init(int numOpenMPThreads)
108 gmx_walltime_accounting_t walltime_accounting;
110 snew(walltime_accounting, 1);
111 walltime_accounting->start_time_stamp = 0;
112 walltime_accounting->start_time_stamp_per_thread = 0;
113 walltime_accounting->elapsed_time = 0;
114 walltime_accounting->nsteps_done = 0;
115 walltime_accounting->numOpenMPThreads = numOpenMPThreads;
117 return walltime_accounting;
121 walltime_accounting_destroy(gmx_walltime_accounting_t walltime_accounting)
123 sfree(walltime_accounting);
127 walltime_accounting_start(gmx_walltime_accounting_t walltime_accounting)
129 walltime_accounting->start_time_stamp = gmx_gettime();
130 walltime_accounting->start_time_stamp_per_thread = gmx_gettime_per_thread();
131 walltime_accounting->elapsed_time = 0;
132 walltime_accounting->nsteps_done = 0;
136 walltime_accounting_end(gmx_walltime_accounting_t walltime_accounting)
138 double now, now_per_thread;
141 now_per_thread = gmx_gettime_per_thread();
143 walltime_accounting->elapsed_time = now - walltime_accounting->start_time_stamp;
144 walltime_accounting->elapsed_time_over_all_threads = now_per_thread - walltime_accounting->start_time_stamp_per_thread;
145 /* For thread-MPI, the per-thread CPU timer makes this just
146 * work. For OpenMP threads, the per-thread CPU timer measurement
147 * needs to be multiplied by the number of OpenMP threads used,
148 * under the current assumption that all regions ever opened
149 * within a process are of the same size, and each thread should
150 * keep one core busy.
152 walltime_accounting->elapsed_time_over_all_threads *= walltime_accounting->numOpenMPThreads;
156 walltime_accounting_get_current_elapsed_time(gmx_walltime_accounting_t walltime_accounting)
158 return gmx_gettime() - walltime_accounting->start_time_stamp;
162 walltime_accounting_get_elapsed_time(gmx_walltime_accounting_t walltime_accounting)
164 return walltime_accounting->elapsed_time;
168 walltime_accounting_get_elapsed_time_over_all_threads(gmx_walltime_accounting_t walltime_accounting)
170 return walltime_accounting->elapsed_time_over_all_threads;
174 walltime_accounting_get_start_time_stamp(gmx_walltime_accounting_t walltime_accounting)
176 return walltime_accounting->start_time_stamp;
180 walltime_accounting_get_nsteps_done(gmx_walltime_accounting_t walltime_accounting)
182 return walltime_accounting->nsteps_done;
186 walltime_accounting_set_nsteps_done(gmx_walltime_accounting_t walltime_accounting,
187 gmx_int64_t nsteps_done)
189 walltime_accounting->nsteps_done = nsteps_done;
195 #if defined HAVE_CLOCK_GETTIME && _POSIX_TIMERS >= 0
196 /* Mac and Windows do not support this. For added fun, Windows
197 * defines _POSIX_TIMERS without actually providing the
202 clock_gettime(CLOCK_REALTIME, &t);
203 seconds = (double) t.tv_sec + 1e-9*(double)t.tv_nsec;
206 #elif defined HAVE_GETTIMEOFDAY
207 // Note that gettimeofday() is deprecated by POSIX, but since Mac
208 // and Windows do not yet support POSIX, we are still stuck.
212 gettimeofday(&t, NULL);
213 seconds = (double) t.tv_sec + 1e-6*(double)t.tv_usec;
219 seconds = time(NULL);
226 gmx_gettime_per_thread()
228 #if defined HAVE_CLOCK_GETTIME && _POSIX_THREAD_CPUTIME >= 0
232 clock_gettime(CLOCK_THREAD_CPUTIME_ID, &t);
233 seconds = (double) t.tv_sec + 1e-9*(double)t.tv_nsec;
237 return gmx_gettime();