| Message ID | 20230818095000.937633-1-liaochang1@huawei.com |
|---|---|
| State | Accepted |
| Commit | ed9571647eff3dd7a53068f83338530959c7ace4 |
| Headers | show |
| Series | cpufreq: stats: Improve the performance of cpufreq_stats_create_table() | expand |
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c index 55c7ffd37d1c..fcb74050711a 100644 --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -243,7 +243,8 @@ void cpufreq_stats_create_table(struct cpufreq_policy *policy) /* Find valid-unique entries */ cpufreq_for_each_valid_entry(pos, policy->freq_table) - if (freq_table_get_index(stats, pos->frequency) == -1) + if ((policy->freq_table_sorted != CPUFREQ_TABLE_UNSORTED) || + (freq_table_get_index(stats, pos->frequency) == -1)) stats->freq_table[i++] = pos->frequency; stats->state_num = i;
In the worst case, the freq_table of policy data is not sorted and contains duplicate frequencies, this means that it needs to iterate through the entire freq_table of policy to ensure each frequency is unique in the freq_table of stats data, this has a time complexity of O(N^2), where N is the number of frequencies in the freq_table of policy. However, if the policy.freq_table is already sorted and contains no duplicate frequencices, it can reduce the time complexity of creating stats.freq_table to O(N), the 'freq_table_sorted' field of policy data can be used to indicate whether the policy.freq_table is sorted. Signed-off-by: Liao Chang <liaochang1@huawei.com> --- drivers/cpufreq/cpufreq_stats.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)