From: tiozhang <zyhtheonly@yeah.net>
Date: Sun, 23 Apr 2023 09:22:22 +0000 (+0800)
Subject: cpufreq: dynamically alloc max_avail_freqs according to time_in_state
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=d760819acbdc9a51c65b52c32cacec3ee9b991aa;p=thirdparty%2Fcollectd.git

cpufreq: dynamically alloc max_avail_freqs according to time_in_state

Signed-off-by: tiozhang <zyhtheonly@yeah.net>
Signed-off-by: luffysong <zsfz_one@163.com>
---

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index 28c7517a9..6b6af7599 100644
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -429,10 +429,6 @@
 #  SubtractGuestState true
 #</Plugin>
 
-#<Plugin cpufreq>
-#  MaxAvailableFreqs "20"
-#</Plugin>
-
 #<Plugin csv>
 #	DataDir "@localstatedir@/lib/@PACKAGE_NAME@/csv"
 #	StoreRates false
diff --git a/src/cpufreq.c b/src/cpufreq.c
index 3b2690810..b8a98a2e2 100644
--- a/src/cpufreq.c
+++ b/src/cpufreq.c
@@ -29,25 +29,9 @@
 #include <sys/sysctl.h>
 #include <sys/types.h>
 #endif
-#define MAX_AVAIL_FREQS "MaxAvailableFreqs"
-
-static int max_avail_freqs = 20; // default MAX_AVAIL_FREQS
-static const char *config_keys[] = {MAX_AVAIL_FREQS};
-static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
-
-static int cpufreq_config(char const *key, char const *value) {
-  if (strcasecmp(key, "MaxAvailableFreqs") == 0) {
-    int freqs = strtol(value, NULL, 0);
-    if (freqs == 0)
-      return -1;
-    max_avail_freqs = freqs;
-  } else
-    return -1;
-
-  return 0;
-}
 
 #if KERNEL_LINUX
+static int max_avail_freqs = 20; // default MAX_AVAIL_FREQS
 
 static int num_cpu;
 
@@ -62,12 +46,6 @@ static void cpufreq_stats_init(void) {
   cpu_data = calloc(num_cpu, sizeof(*cpu_data));
   if (cpu_data == NULL)
     return;
-  for (int i = 0; i < num_cpu; i++) {
-    cpu_data[i].time_state =
-        calloc(max_avail_freqs, sizeof(value_to_rate_state_t));
-    if (cpu_data[i].time_state == NULL)
-      return;
-  }
 
   report_p_stats = true;
 
@@ -84,6 +62,25 @@ static void cpufreq_stats_init(void) {
              filename);
       report_p_stats = false;
       break;
+    } else {
+      /* Count the number of lines in the file content:
+       * /sys/devices/system/cpu/cpu%d/cpufreq/stats/time_in_state */
+      FILE *fh = fopen(filename, "r");
+      if (fh == NULL) {
+        ERROR("cpufreq plugin: File %s not exists or no access.", filename);
+        break;
+      }
+      int state_count = 0;
+      char line[DATA_MAX_NAME_LEN] = {0};
+      while (fgets(line, sizeof(line), fh) != NULL) {
+        state_count++;
+      }
+      fclose(fh);
+
+      /* variable: max_avail_freqs, takes the maximum value of the actual
+       * statistics. */
+      max_avail_freqs =
+          state_count > max_avail_freqs ? state_count : max_avail_freqs;
     }
 
     snprintf(filename, sizeof(filename),
@@ -97,6 +94,18 @@ static void cpufreq_stats_init(void) {
       break;
     }
   }
+
+  for (int i = 0; i < num_cpu; i++) {
+    cpu_data[i].time_state =
+        calloc(max_avail_freqs, sizeof(value_to_rate_state_t));
+    if (cpu_data[i].time_state == NULL) {
+      ERROR("cpufreq plugin: time_state memory allocation failed. P-State "
+            "statistics will not be reported.");
+      report_p_stats = false;
+      return;
+    }
+  }
+
   return;
 }
 #endif /* KERNEL_LINUX */
@@ -204,7 +213,7 @@ static void cpufreq_read_stats(int cpu) {
 
     if (state_index >= max_avail_freqs) {
       NOTICE("cpufreq plugin: Found too many frequency states (%d > %d). "
-             "Plugin needs to be recompiled. Please open a bug report for "
+             "Please open a bug report for "
              "this.",
              (state_index + 1), max_avail_freqs);
       break;
@@ -271,7 +280,5 @@ static int cpufreq_read(void) {
 
 void module_register(void) {
   plugin_register_init("cpufreq", cpufreq_init);
-  plugin_register_config("cpufreq", cpufreq_config, config_keys,
-                         config_keys_num);
   plugin_register_read("cpufreq", cpufreq_read);
 }