Re: [PATCH V4 1/2] cpufreq: Handle sorted frequency tables more efficiently
From: Rafael J. Wysocki <hidden>
Date: 2016-06-23 00:24:42
Also in:
lkml
On Tuesday, June 07, 2016 03:55:14 PM Viresh Kumar wrote:
quoted hunk ↗ jump to hunk
cpufreq drivers aren't required to provide a sorted frequency table today, and even the ones which provide a sorted table aren't handled efficiently by cpufreq core. This patch adds infrastructure to verify if the freq-table provided by the drivers is sorted or not, and use efficient helpers if they are sorted. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/cpufreq/freq_table.c | 67 +++++++++- include/linux/cpufreq.h | 284 ++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 343 insertions(+), 8 deletions(-)diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c index eac8bcbdaad1..0c1139a5f33a 100644 --- a/drivers/cpufreq/freq_table.c +++ b/drivers/cpufreq/freq_table.c@@ -113,9 +113,9 @@ int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy) } EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify); -int cpufreq_frequency_table_target(struct cpufreq_policy *policy, - unsigned int target_freq, - unsigned int relation) +int cpufreq_table_find_index_unsorted(struct cpufreq_policy *policy,
Is the "find" part really necessary in this name?
quoted hunk ↗ jump to hunk
+ unsigned int target_freq, + unsigned int relation) { struct cpufreq_frequency_table optimal = { .driver_data = ~0,@@ -205,7 +205,7 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy, table[index].frequency); return index; } -EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target); +EXPORT_SYMBOL_GPL(cpufreq_table_find_index_unsorted); int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy, unsigned int freq)@@ -297,13 +297,70 @@ struct freq_attr *cpufreq_generic_attr[] = { }; EXPORT_SYMBOL_GPL(cpufreq_generic_attr); +static void set_freq_table_sorted(struct cpufreq_policy *policy) +{ + struct cpufreq_frequency_table *pos, *table = policy->freq_table; + struct cpufreq_frequency_table *prev = NULL; + int ascending = 0; + + cpufreq_for_each_valid_entry(pos, table) { + if (!prev) { + prev = pos; + continue; + } + + if (pos->frequency == prev->frequency) { + pr_warn("Duplicate freq-table entries: %u\n", + pos->frequency);
Shouldn't cpufreq_table_validate_and_show() simply return an error in this case? Or do we know about any drivers having this problem potentially?
+ continue;
+ }
+
+ /* Frequency increased from prev to pos */
+ if (pos->frequency > prev->frequency) {
+ /* But frequency was decreasing earlier */
+ if (ascending < 0) {
+ policy->freq_table_sorted = false;
+ pr_debug("Freq table is unsorted\n");
+ return;
+ }
+
+ ascending++;
+ } else {
+ /* Frequency decreased from prev to pos */
+
+ /* But frequency was increasing earlier */
+ if (ascending > 0) {
+ policy->freq_table_sorted = false;
+ pr_debug("Freq table is unsorted\n");
+ return;
+ }
+
+ ascending--;
+ }
+
+ prev = pos;
+ }
+
+ policy->freq_table_sorted = true;
+
+ if (ascending > 0)
+ policy->freq_table_sorted_ascending = true;So what about making policy->freq_table_sorted an enum instead of using two fields?
quoted hunk ↗ jump to hunk
+ else + policy->freq_table_sorted_ascending = false; + + pr_debug("Freq table is sorted in %s order\n", + ascending > 0 ? "ascending" : "descending"); +} + int cpufreq_table_validate_and_show(struct cpufreq_policy *policy, struct cpufreq_frequency_table *table) { int ret = cpufreq_frequency_table_cpuinfo(policy, table); - if (!ret) + if (!ret) { policy->freq_table = table; + set_freq_table_sorted(policy); + } return ret; }diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index c378776628b4..5133570e86f2 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h@@ -86,7 +86,11 @@ struct cpufreq_policy { * called, but you're in IRQ context */ struct cpufreq_user_policy user_policy; + + /* Freq-table and its flags */ struct cpufreq_frequency_table *freq_table; + bool freq_table_sorted; + bool freq_table_sorted_ascending; struct list_head policy_list; struct kobject kobj;@@ -597,9 +601,9 @@ int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, struct cpufreq_frequency_table *table); int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy); -int cpufreq_frequency_table_target(struct cpufreq_policy *policy, - unsigned int target_freq, - unsigned int relation); +int cpufreq_table_find_index_unsorted(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation); int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy, unsigned int freq);@@ -610,6 +614,280 @@ int cpufreq_boost_trigger_state(int state); int cpufreq_boost_enabled(void); int cpufreq_enable_boost_support(void); bool policy_has_boost_freq(struct cpufreq_policy *policy); + +static inline bool freq_is_invalid(struct cpufreq_policy *policy, unsigned int frequency) +{ + if (unlikely(frequency == CPUFREQ_ENTRY_INVALID)) + return true; + + if (unlikely((frequency < policy->min) || (frequency > policy->max))) + return true;
This is confusing. A frequency beyond min..max is not invalid, it is out of bounds.
+
+ return false;
+}
+
+/* Find lowest freq at or above target in a table in ascending order */
+static inline int cpufreq_table_find_index_al(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct cpufreq_frequency_table *table = policy->freq_table;
+ unsigned int freq;
+ int i, best = -1;
+
+ for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ freq = table[i].frequency;
+
+ if (freq_is_invalid(policy, freq))
+ continue;
+
+ if (freq >= target_freq)
+ return i;
+
+ best = i;
+ }
+
+ if (best == -1) {
+ WARN(1, "Invalid frequency table: %d\n", policy->cpu);After a successful cpufreq_table_validate_and_show() that should be impossible, shouldn't it?
+ return -EINVAL;
+ }
+
+ return best;
+}
+
+/* Find lowest freq at or above target in a table in descending order */
+static inline int cpufreq_table_find_index_dl(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct cpufreq_frequency_table *table = policy->freq_table;
+ unsigned int freq;
+ int i, best = -1;
+
+ for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ freq = table[i].frequency;
+
+ if (freq_is_invalid(policy, freq))
+ continue;
+
+ if (freq == target_freq)
+ return i;
+
+ if (freq > target_freq) {
+ best = i;
+ continue;
+ }
+
+ /* No freq found below target_freq */
+ if (best == -1)
+ return i;
+
+ return best;
+ }
+
+ if (best == -1) {
+ WARN(1, "Invalid frequency table: %d\n", policy->cpu);
+ return -EINVAL;
+ }
+
+ return best;
+}
+
+/* Works only on sorted freq-tables */
+static inline int cpufreq_table_find_index_l(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ if (policy->freq_table_sorted_ascending)
+ return cpufreq_table_find_index_al(policy, target_freq);
+ else
+ return cpufreq_table_find_index_dl(policy, target_freq);
+}
+
+/* Find highest freq at or below target in a table in ascending order */
+static inline int cpufreq_table_find_index_ah(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct cpufreq_frequency_table *table = policy->freq_table;
+ unsigned int freq;
+ int i, best = -1;
+
+ for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ freq = table[i].frequency;
+
+ if (freq_is_invalid(policy, freq))
+ continue;
+
+ if (freq == target_freq)
+ return i;
+
+ if (freq < target_freq) {
+ best = i;
+ continue;
+ }
+
+ /* No freq found below target_freq */
+ if (best == -1)
+ return i;
+
+ return best;
+ }
+
+ if (best == -1) {
+ WARN(1, "Invalid frequency table: %d\n", policy->cpu);
+ return -EINVAL;
+ }
+
+ return best;
+}
+
+/* Find highest freq at or below target in a table in descending order */
+static inline int cpufreq_table_find_index_dh(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct cpufreq_frequency_table *table = policy->freq_table;
+ unsigned int freq;
+ int i, best = -1;
+
+ for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ freq = table[i].frequency;
+
+ if (freq_is_invalid(policy, freq))
+ continue;
+
+ if (freq <= target_freq)
+ return i;
+
+ best = i;
+ }
+
+ if (best == -1) {
+ WARN(1, "Invalid frequency table: %d\n", policy->cpu);
+ return -EINVAL;
+ }
+
+ return best;
+}I still don't see a reason for min/max checking in these routines. So what is the reason?
+
+/* Works only on sorted freq-tables */
+static inline int cpufreq_table_find_index_h(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ if (policy->freq_table_sorted_ascending)
+ return cpufreq_table_find_index_ah(policy, target_freq);
+ else
+ return cpufreq_table_find_index_dh(policy, target_freq);
+}
+
+/* Find closest freq to target in a table in ascending order */
+static inline int cpufreq_table_find_index_ac(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct cpufreq_frequency_table *table = policy->freq_table;
+ unsigned int freq;
+ int i, best = -1;
+
+ for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ freq = table[i].frequency;
+
+ if (freq_is_invalid(policy, freq))
+ continue;
+
+ if (freq == target_freq)
+ return i;
+
+ if (freq < target_freq) {
+ best = i;
+ continue;
+ }
+
+ /* No freq found below target_freq */
+ if (best == -1)
+ return i;
+
+ /* Choose the closest freq */
+ if (target_freq - table[best].frequency > freq - target_freq)
+ return i;
+
+ return best;
+ }
+
+ if (best == -1) {Can we actually get here?
+ WARN(1, "Invalid frequency table: %d\n", policy->cpu);
+ return -EINVAL;
+ }
+
+ return best;
+}
+
+/* Find closest freq to target in a table in descending order */
+static inline int cpufreq_table_find_index_dc(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct cpufreq_frequency_table *table = policy->freq_table;
+ unsigned int freq;
+ int i, best = -1;
+
+ for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ freq = table[i].frequency;
+
+ if (freq_is_invalid(policy, freq))
+ continue;
+
+ if (freq == target_freq)
+ return i;
+
+ if (freq > target_freq) {
+ best = i;
+ continue;
+ }
+
+ /* No freq found below target_freq */
+ if (best == -1)
+ return i;
+
+ /* Choose the closest freq */
+ if (target_freq - table[best].frequency > freq - target_freq)
+ return i;
+
+ return best;
+ }
+
+ if (best == -1) {
+ WARN(1, "Invalid frequency table: %d\n", policy->cpu);
+ return -EINVAL;
+ }
+
+ return best;
+}
+
+/* Works only on sorted freq-tables */
+static inline int cpufreq_table_find_index_c(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ if (policy->freq_table_sorted_ascending)
+ return cpufreq_table_find_index_ac(policy, target_freq);
+ else
+ return cpufreq_table_find_index_dc(policy, target_freq);
+}
+
+static inline int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ if (unlikely(!policy->freq_table_sorted))
+ return cpufreq_table_find_index_unsorted(policy, target_freq,
+ relation);
+
+ switch (relation) {
+ case CPUFREQ_RELATION_L:
+ return cpufreq_table_find_index_l(policy, target_freq);
+ case CPUFREQ_RELATION_H:
+ return cpufreq_table_find_index_h(policy, target_freq);
+ case CPUFREQ_RELATION_C:
+ return cpufreq_table_find_index_c(policy, target_freq);
+ default:
+ pr_err("%s: Invalid relation: %d\n", __func__, relation);
+ return -EINVAL;
+ }
+}
#else
static inline int cpufreq_boost_trigger_state(int state)
{Thanks, Rafael