When using intel_pstate driver, "scaling_available_freqs" attr is not
exported to sysfs. It causes assertion of idlestat due to memory of
struct cpufreq_pstate was not allocated.
Allocate struct cpufreq_pstate dynamically when getting frequency
information from trace file instead of parsing available frequencies
from sysfs
Signed-off-by: Pi-Cheng Chen <pi-cheng.c...@linaro.org>
---
idlestat.c | 109 ++++++++++++++++++++++++++-----------------------------------
1 file changed, 47 insertions(+), 62 deletions(-)
diff --git a/idlestat.c b/idlestat.c
index bba8951..0046063 100644
--- a/idlestat.c
+++ b/idlestat.c
@@ -509,8 +509,8 @@ static void release_pstate_info(struct cpufreq_pstates
*pstates, int nrcpus)
}
/**
- * build_pstate_info - parse cpufreq sysfs entries and build per-CPU
- * structs to maintain statistics of P-state transitions
+ * build_pstate_info - allocate and initialize per-CPU structs to
+ * maintain statistics of P-state transitions
* @nrcpus: number of CPUs
*
* Return: per-CPU array of structs (success) or NULL (error)
@@ -526,55 +526,8 @@ static struct cpufreq_pstates *build_pstate_info(int
nrcpus)
memset(pstates, 0, sizeof(*pstates) * nrcpus);
for (cpu = 0; cpu < nrcpus; cpu++) {
- struct cpufreq_pstate *pstate;
- int nrfreq;
- char *fpath, *freq, line[256];
- FILE *sc_av_freq;
-
- if (asprintf(&fpath, CPUFREQ_AVFREQ_PATH_FORMAT, cpu) < 0)
- goto clean_exit;
-
- /* read scaling_available_frequencies for the CPU */
- sc_av_freq = fopen(fpath, "r");
- free(fpath);
- if (!sc_av_freq) {
- fprintf(stderr, "warning: P-states not supported for "
- "CPU%d\n", cpu);
- continue;
- }
- freq = fgets(line, sizeof(line)/sizeof(line[0]), sc_av_freq);
- fclose(sc_av_freq);
- if (!freq) {
- /* unlikely to be here, but just in case... */
- fprintf(stderr, "warning: P-state info not found for "
- "CPU%d\n", cpu);
- continue;
- }
-
- /* tokenize line and populate each frequency */
- nrfreq = 0;
- pstate = NULL;
- while ((freq = strtok(freq, "\n ")) != NULL) {
- struct cpufreq_pstate *tmp = realloc(pstate,
sizeof(*pstate) * (nrfreq+1));
- if (!tmp)
- goto clean_exit;
- pstate = tmp;
-
- /* initialize pstate record */
- pstate[nrfreq].id = nrfreq;
- pstate[nrfreq].freq = atol(freq);
- pstate[nrfreq].count = 0;
- pstate[nrfreq].min_time = DBL_MAX;
- pstate[nrfreq].max_time = 0.;
- pstate[nrfreq].avg_time = 0.;
- pstate[nrfreq].duration = 0.;
- nrfreq++;
- freq = NULL;
- }
-
- /* now populate cpufreq_pstates for this CPU */
- pstates[cpu].pstate = pstate;
- pstates[cpu].max = nrfreq;
+ pstates[cpu].pstate = NULL;
+ pstates[cpu].max = 0;
pstates[cpu].current = -1; /* unknown */
pstates[cpu].idle = -1; /* unknown */
pstates[cpu].time_enter = 0.;
@@ -582,10 +535,43 @@ static struct cpufreq_pstates *build_pstate_info(int
nrcpus)
}
return pstates;
+}
-clean_exit:
- release_pstate_info(pstates, nrcpus);
- return NULL;
+/**
+ * alloc_pstate - allocate and initialize pstate struct to
+ * maintain statistics of P-state transitions
+ * @pstates: per-CPU P-state statistics struct
+ * @freq: frequency for which the newly pstate is allocated
+ *
+ * Return: the index of the newly allocated pstate struct
+ */
+static int alloc_pstate(struct cpufreq_pstates *pstates, unsigned int freq)
+{
+ struct cpufreq_pstate *pstate, *tmp;
+ int nrfreq;
+
+ pstate = pstates->pstate;
+ nrfreq = pstates->max;
+
+ tmp = realloc(pstate, sizeof(*pstate) * (nrfreq + 1));
+ if (!tmp) {
+ perror("realloc pstate");
+ return -1;
+ }
+ pstate = tmp;
+
+ pstate[nrfreq].id = nrfreq;
+ pstate[nrfreq].freq = freq;
+ pstate[nrfreq].count = 0;
+ pstate[nrfreq].min_time = DBL_MAX;
+ pstate[nrfreq].max_time = 0;
+ pstate[nrfreq].avg_time = 0;
+ pstate[nrfreq].duration = 0;
+
+ pstates->pstate = tmp;
+ pstates->max = nrfreq + 1;
+
+ return nrfreq;
}
static int get_current_pstate(struct cpuidle_datas *datas, int cpu,
@@ -660,6 +646,9 @@ static void cpu_change_pstate(struct cpuidle_datas *datas,
int cpu,
cur = get_current_pstate(datas, cpu, &ps, &p);
next = freq_to_pstate_index(ps, freq);
+ if (next < 0)
+ next = alloc_pstate(ps, freq);
+ assert(next >= 0);
switch (cur) {
case 1:
@@ -711,7 +700,6 @@ static int store_data(double time, int state, int cpu,
struct cpuidle_datas *datas, int count)
{
struct cpuidle_cstates *cstates = &datas->cstates[cpu];
- struct cpufreq_pstate *pstate = datas->pstates[cpu].pstate;
struct cpuidle_cstate *cstate;
struct cpuidle_data *data, *tmp;
int nrdata, last_cstate = cstates->last_cstate;
@@ -774,9 +762,8 @@ static int store_data(double time, int state, int cpu,
/* need indication if CPU is idle or not */
cstates->last_cstate = -1;
- /* update P-state stats if supported */
- if (pstate)
- cpu_pstate_running(datas, cpu, time);
+ /* update P-state stats */
+ cpu_pstate_running(datas, cpu, time);
return 0;
}
@@ -794,9 +781,8 @@ static int store_data(double time, int state, int cpu,
cstates->cstate_max = MAX(cstates->cstate_max, state);
cstates->last_cstate = state;
cstates->wakeirq = NULL;
- /* update P-state stats if supported */
- if (pstate)
- cpu_pstate_idle(datas, cpu, time);
+ /* update P-state stats*/
+ cpu_pstate_idle(datas, cpu, time);
return 0;
}
@@ -966,7 +952,6 @@ static struct cpuidle_datas *idlestat_load(struct
program_options *options)
} else if (strstr(buffer, "cpu_frequency")) {
assert(sscanf(buffer, TRACE_FORMAT, &time, &freq,
&cpu) == 3);
- assert(datas->pstates[cpu].pstate != NULL);
cpu_change_pstate(datas, cpu, freq, time);
count++;
continue;
--
1.9.1
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