1 /* 2 * Copyright 2009, Intel Corporation 3 * Copyright 2009, Sun Microsystems, Inc 4 * 5 * This file is part of PowerTOP 6 * 7 * This program file is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the 9 * Free Software Foundation; version 2 of the License. 10 * 11 * This program is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program in a file named COPYING; if not, write to the 18 * Free Software Foundation, Inc., 19 * 51 Franklin Street, Fifth Floor, 20 * Boston, MA 02110-1301 USA 21 * 22 * Authors: 23 * Arjan van de Ven <arjan@linux.intel.com> 24 * Eric C Saxe <eric.saxe@sun.com> 25 * Aubrey Li <aubrey.li@intel.com> 26 */ 27 28 /* 29 * GPL Disclaimer 30 * 31 * For the avoidance of doubt, except that if any license choice other 32 * than GPL or LGPL is available it will apply instead, Sun elects to 33 * use only the General Public License version 2 (GPLv2) at this time 34 * for any software where a choice of GPL license versions is made 35 * available with the language indicating that GPLv2 or any later 36 * version may be used, or where a choice of which version of the GPL 37 * is applied is otherwise unspecified. 38 */ 39 40 #include <string.h> 41 #include <dtrace.h> 42 #include "powertop.h" 43 44 static dtrace_hdl_t *dtp; 45 46 /* 47 * Buffer containing DTrace program to track CPU idle state transitions 48 */ 49 static const char *dtp_cpuidle = 50 ":::idle-state-transition" 51 "/arg0 != 0/" 52 "{" 53 " self->start = timestamp;" 54 " self->state = arg0;" 55 "}" 56 "" 57 ":::idle-state-transition" 58 "/arg0 == 0 && self->start/" 59 "{" 60 " @number[self->state] = count();" 61 " @times[self->state] = sum((timestamp - self->start)/1000000);" 62 " self->start = 0;" 63 " self->state = 0;" 64 "}"; 65 66 /* 67 * Same as above but only for a specific CPU 68 */ 69 static const char *dtp_cpuidle_c = 70 ":::idle-state-transition" 71 "/cpu == $0 &&" 72 " arg0 != 0/" 73 "{" 74 " self->start = timestamp;" 75 " self->state = arg0;" 76 "}" 77 "" 78 ":::idle-state-transition" 79 "/cpu == $0 &&" 80 " arg0 == 0 && self->start/" 81 "{" 82 " @number[self->state] = count();" 83 " @times[self->state] = sum((timestamp - self->start)/1000000);" 84 " self->start = 0;" 85 " self->state = 0;" 86 "}"; 87 88 static int pt_cpuidle_dtrace_walk(const dtrace_aggdata_t *, void *); 89 90 /* 91 * Perform setup necessary to track CPU idle state transitions 92 */ 93 int 94 pt_cpuidle_stat_prepare(void) 95 { 96 dtrace_prog_t *prog; 97 dtrace_proginfo_t info; 98 dtrace_optval_t statustime; 99 int err; 100 char *prog_ptr; 101 102 if ((dtp = dtrace_open(DTRACE_VERSION, 0, &err)) == NULL) { 103 pt_error("%s : cannot open dtrace library: %s\n", __FILE__, 104 dtrace_errmsg(NULL, err)); 105 return (-1); 106 } 107 108 /* 109 * Execute different scripts (defined above) depending on 110 * user specified options. 111 */ 112 if (PTOP_ON_CPU) 113 prog_ptr = (char *)dtp_cpuidle_c; 114 else 115 prog_ptr = (char *)dtp_cpuidle; 116 117 if ((prog = dtrace_program_strcompile(dtp, prog_ptr, 118 DTRACE_PROBESPEC_NAME, 0, g_argc, g_argv)) == NULL) { 119 pt_error("%s : C-State DTrace probes unavailable\n", __FILE__); 120 return (dtrace_errno(dtp)); 121 } 122 123 if (dtrace_program_exec(dtp, prog, &info) == -1) { 124 pt_error("%s : failed to enable C State probes\n", __FILE__); 125 return (dtrace_errno(dtp)); 126 } 127 128 if (dtrace_setopt(dtp, "aggsize", "128k") == -1) { 129 pt_error("%s : failed to set C-state 'aggsize'\n", __FILE__); 130 } 131 132 if (dtrace_setopt(dtp, "aggrate", "0") == -1) { 133 pt_error("%s : failed to set C-state'aggrate'\n", __FILE__); 134 } 135 136 if (dtrace_setopt(dtp, "aggpercpu", 0) == -1) { 137 pt_error("%s : failed to set C-state 'aggpercpu'\n", __FILE__); 138 } 139 140 if (dtrace_go(dtp) != 0) { 141 pt_error("%s : failed to start C-state observation", __FILE__); 142 return (dtrace_errno(dtp)); 143 } 144 145 if (dtrace_getopt(dtp, "statusrate", &statustime) == -1) { 146 pt_error("%s : failed to get C-state 'statusrate'\n", __FILE__); 147 return (dtrace_errno(dtp)); 148 } 149 150 return (0); 151 } 152 153 /* 154 * The DTrace probes have been enabled, and are tracking CPU idle state 155 * transitions. Take a snapshot of the aggregations, and invoke the aggregation 156 * walker to process any records. The walker does most of the accounting work 157 * chalking up time spent into the g_cstate_info structure. 158 */ 159 int 160 pt_cpuidle_stat_collect(double interval) 161 { 162 int i; 163 hrtime_t t = 0; 164 165 /* 166 * Assume that all the time spent in this interval will 167 * be the default "0" state. The DTrace walker will reallocate 168 * time out of the default bucket as it processes aggregation 169 * records for time spent in other states. 170 */ 171 g_cstate_info[0].total_time = (long)(interval * g_ncpus_observed * 172 1000); 173 174 if (dtrace_status(dtp) == -1) 175 return (-1); 176 177 if (dtrace_aggregate_snap(dtp) != 0) 178 pt_error("%s : failed to add to aggregation", __FILE__); 179 180 if (dtrace_aggregate_walk_keyvarsorted(dtp, pt_cpuidle_dtrace_walk, 181 NULL) != 0) 182 pt_error("%s : failed to sort aggregation", __FILE__); 183 184 dtrace_aggregate_clear(dtp); 185 186 /* 187 * Populate g_cstate_info with the correct amount of time spent 188 * in each C state and update the number of C states in g_max_cstate 189 */ 190 g_total_c_time = 0; 191 for (i = 0; i < NSTATES; i++) { 192 if (g_cstate_info[i].total_time > 0) { 193 g_total_c_time += g_cstate_info[i].total_time; 194 if (i > g_max_cstate) 195 g_max_cstate = i; 196 if (g_cstate_info[i].last_time > t) { 197 t = g_cstate_info[i].last_time; 198 g_longest_cstate = i; 199 } 200 } 201 } 202 203 return (0); 204 } 205 206 /* 207 * DTrace aggregation walker that sorts through a snapshot of data records 208 * collected during firings of the idle-state-transition probe. 209 * 210 * XXX A way of querying the current idle state for a CPU is needed in addition 211 * to logic similar to that in cpufreq.c 212 */ 213 /*ARGSUSED*/ 214 static int 215 pt_cpuidle_dtrace_walk(const dtrace_aggdata_t *data, void *arg) 216 { 217 dtrace_aggdesc_t *aggdesc = data->dtada_desc; 218 dtrace_recdesc_t *rec; 219 uint64_t n = 0; 220 int32_t state; 221 int i; 222 223 rec = &aggdesc->dtagd_rec[1]; 224 /* LINTED - alignment */ 225 state = *(int32_t *)(data->dtada_data + rec->dtrd_offset); 226 227 if (strcmp(aggdesc->dtagd_name, "number") == 0) { 228 for (i = 0; i < g_ncpus; i++) { 229 /* LINTED - alignment */ 230 n += *((uint64_t *)(data->dtada_percpu[i])); 231 } 232 g_total_events += n; 233 g_cstate_info[state].events += n; 234 } 235 else 236 if (strcmp(aggdesc->dtagd_name, "times") == 0) { 237 for (i = 0; i < g_ncpus; i++) { 238 /* LINTED - alignment */ 239 n += *((uint64_t *)(data->dtada_percpu[i])); 240 } 241 g_cstate_info[state].last_time = n; 242 g_cstate_info[state].total_time += n; 243 if (g_cstate_info[0].total_time >= n) 244 g_cstate_info[0].total_time -= n; 245 } 246 247 return (DTRACE_AGGWALK_NEXT); 248 } 249