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authorAlexander Clouter <alex@digriz.org.uk>2006-03-22 05:00:18 -0500
committerDominik Brodowski <linux@dominikbrodowski.net>2006-03-26 03:18:18 -0500
commita159b82770ab84e1b5e0306fa65e158188492b16 (patch)
tree93c0c6cd2438e8b20015bfb3444fa930b760452c /drivers
parent08a28e2e98aa821cf6f15f8a267beb2f33377bb9 (diff)
[PATCH] cpufreq_conservative: alternative initialise approach
Venki, author of cpufreq_ondemand, came up with a neater way to remove the initialiser code from the main loop of my code and out to the point when the governor is actually initialised. Not only does it look but it also feels cleaner, plus its simpler to understand. It also saves a bunch of pointless conditional statements in the main loop. Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/cpufreq/cpufreq_conservative.c55
1 files changed, 18 insertions, 37 deletions
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 7498f2506ade..a152d2c46be7 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -65,6 +65,8 @@ struct cpu_dbs_info_s {
65 unsigned int prev_cpu_idle_up; 65 unsigned int prev_cpu_idle_up;
66 unsigned int prev_cpu_idle_down; 66 unsigned int prev_cpu_idle_down;
67 unsigned int enable; 67 unsigned int enable;
68 unsigned int down_skip;
69 unsigned int requested_freq;
68}; 70};
69static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); 71static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
70 72
@@ -297,35 +299,12 @@ static void dbs_check_cpu(int cpu)
297 unsigned int tmp_idle_ticks, total_idle_ticks; 299 unsigned int tmp_idle_ticks, total_idle_ticks;
298 unsigned int freq_step; 300 unsigned int freq_step;
299 unsigned int freq_down_sampling_rate; 301 unsigned int freq_down_sampling_rate;
300 static unsigned short down_skip[NR_CPUS];
301 static unsigned int requested_freq[NR_CPUS];
302 static unsigned int init_flag = NR_CPUS;
303 struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu); 302 struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
304 struct cpufreq_policy *policy; 303 struct cpufreq_policy *policy;
305 304
306 if (!this_dbs_info->enable) 305 if (!this_dbs_info->enable)
307 return; 306 return;
308 307
309 if ( init_flag != 0 ) {
310 for_each_cpu(init_flag) {
311 down_skip[init_flag] = 0;
312 /* I doubt a CPU exists with a freq of 0hz :) */
313 requested_freq[init_flag] = 0;
314 }
315 init_flag = 0;
316 }
317
318 /*
319 * If its a freshly initialised cpu we setup requested_freq. This
320 * check could be avoided if we did not care about a first time
321 * stunted increase in CPU speed when there is a load. I feel we
322 * should be initialising this to something. The removal of a CPU
323 * is not a problem, after a short time the CPU should settle down
324 * to a 'natural' frequency.
325 */
326 if (requested_freq[cpu] == 0)
327 requested_freq[cpu] = this_dbs_info->cur_policy->cur;
328
329 policy = this_dbs_info->cur_policy; 308 policy = this_dbs_info->cur_policy;
330 309
331 /* 310 /*
@@ -360,12 +339,12 @@ static void dbs_check_cpu(int cpu)
360 usecs_to_jiffies(dbs_tuners_ins.sampling_rate); 339 usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
361 340
362 if (idle_ticks < up_idle_ticks) { 341 if (idle_ticks < up_idle_ticks) {
363 down_skip[cpu] = 0; 342 this_dbs_info->down_skip = 0;
364 this_dbs_info->prev_cpu_idle_down = 343 this_dbs_info->prev_cpu_idle_down =
365 this_dbs_info->prev_cpu_idle_up; 344 this_dbs_info->prev_cpu_idle_up;
366 345
367 /* if we are already at full speed then break out early */ 346 /* if we are already at full speed then break out early */
368 if (requested_freq[cpu] == policy->max) 347 if (this_dbs_info->requested_freq == policy->max)
369 return; 348 return;
370 349
371 freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100; 350 freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100;
@@ -374,18 +353,18 @@ static void dbs_check_cpu(int cpu)
374 if (unlikely(freq_step == 0)) 353 if (unlikely(freq_step == 0))
375 freq_step = 5; 354 freq_step = 5;
376 355
377 requested_freq[cpu] += freq_step; 356 this_dbs_info->requested_freq += freq_step;
378 if (requested_freq[cpu] > policy->max) 357 if (this_dbs_info->requested_freq > policy->max)
379 requested_freq[cpu] = policy->max; 358 this_dbs_info->requested_freq = policy->max;
380 359
381 __cpufreq_driver_target(policy, requested_freq[cpu], 360 __cpufreq_driver_target(policy, this_dbs_info->requested_freq,
382 CPUFREQ_RELATION_H); 361 CPUFREQ_RELATION_H);
383 return; 362 return;
384 } 363 }
385 364
386 /* Check for frequency decrease */ 365 /* Check for frequency decrease */
387 down_skip[cpu]++; 366 this_dbs_info->down_skip++;
388 if (down_skip[cpu] < dbs_tuners_ins.sampling_down_factor) 367 if (this_dbs_info->down_skip < dbs_tuners_ins.sampling_down_factor)
389 return; 368 return;
390 369
391 /* Check for frequency decrease */ 370 /* Check for frequency decrease */
@@ -399,7 +378,7 @@ static void dbs_check_cpu(int cpu)
399 378
400 /* Scale idle ticks by 100 and compare with up and down ticks */ 379 /* Scale idle ticks by 100 and compare with up and down ticks */
401 idle_ticks *= 100; 380 idle_ticks *= 100;
402 down_skip[cpu] = 0; 381 this_dbs_info->down_skip = 0;
403 382
404 freq_down_sampling_rate = dbs_tuners_ins.sampling_rate * 383 freq_down_sampling_rate = dbs_tuners_ins.sampling_rate *
405 dbs_tuners_ins.sampling_down_factor; 384 dbs_tuners_ins.sampling_down_factor;
@@ -412,7 +391,7 @@ static void dbs_check_cpu(int cpu)
412 * or if we 'cannot' reduce the speed as the user might want 391 * or if we 'cannot' reduce the speed as the user might want
413 * freq_step to be zero 392 * freq_step to be zero
414 */ 393 */
415 if (requested_freq[cpu] == policy->min 394 if (this_dbs_info->requested_freq == policy->min
416 || dbs_tuners_ins.freq_step == 0) 395 || dbs_tuners_ins.freq_step == 0)
417 return; 396 return;
418 397
@@ -422,11 +401,11 @@ static void dbs_check_cpu(int cpu)
422 if (unlikely(freq_step == 0)) 401 if (unlikely(freq_step == 0))
423 freq_step = 5; 402 freq_step = 5;
424 403
425 requested_freq[cpu] -= freq_step; 404 this_dbs_info->requested_freq -= freq_step;
426 if (requested_freq[cpu] < policy->min) 405 if (this_dbs_info->requested_freq < policy->min)
427 requested_freq[cpu] = policy->min; 406 this_dbs_info->requested_freq = policy->min;
428 407
429 __cpufreq_driver_target(policy, requested_freq[cpu], 408 __cpufreq_driver_target(policy, this_dbs_info->requested_freq,
430 CPUFREQ_RELATION_H); 409 CPUFREQ_RELATION_H);
431 return; 410 return;
432 } 411 }
@@ -489,6 +468,8 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
489 = j_dbs_info->prev_cpu_idle_up; 468 = j_dbs_info->prev_cpu_idle_up;
490 } 469 }
491 this_dbs_info->enable = 1; 470 this_dbs_info->enable = 1;
471 this_dbs_info->down_skip = 0;
472 this_dbs_info->requested_freq = policy->cur;
492 sysfs_create_group(&policy->kobj, &dbs_attr_group); 473 sysfs_create_group(&policy->kobj, &dbs_attr_group);
493 dbs_enable++; 474 dbs_enable++;
494 /* 475 /*