Use the MSR/SMI counter on Intel's processor to detect/count SMIs. It is
based on turbostat's implementation.
SMI counting is enabled via --smi argument. When enabled, and additional
field is added on both regular and verbose ouput.
On the regular output, a SMI column shows how many SMIs occurred on
each CPU during cyclictest's execution. For example:
policy: fifo: loadavg: 0.09 0.05 0.02 1/194 2288
T: 0 ( 2285) P:80 I:1000 C: 9975 Min: 2 Act: 3 Avg: 4 Max: 20831 SMI: 2
T: 1 ( 2286) P:80 I:1500 C: 6650 Min: 2 Act: 2 Avg: 5 Max: 19910 SMI: 2
T: 2 ( 2287) P:80 I:2000 C: 4987 Min: 2 Act: 2 Avg: 6 Max: 20811 SMI: 2
T: 3 ( 2288) P:80 I:2500 C: 3990 Min: 2 Act: 3 Avg: 7 Max: 20322 SMI: 2
On verbose output, the last column shows how many SMIs occurred
on each loop. For example:
[ CPU | Loop | Lat | SMIs ]
0: 2156: 2 0
0: 2157: 2 0
0: 2158: 2 0
0: 2159: 20981 2
1: 1433: 2 0
1: 1434: 2 0
1: 1435: 2 0
1: 1436: 3 0
1: 1437: 2 0
1: 1438: 2 0
1: 1439: 20249 2
Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
---
src/cyclictest/cyclictest.c | 229 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 219 insertions(+), 10 deletions(-)
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index f5a67dc..df3db2a 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -111,6 +111,13 @@ extern int clock_nanosleep(clockid_t __clock_id, int __flags,
#define KVARNAMELEN 32
#define KVALUELEN 32
+#if (defined(__i386__) || defined(__x86_64__))
+#define ARCH_HAS_SMI_COUNTER
+#endif
+
+#define MSR_SMI_COUNT 0x00000034
+#define MSR_SMI_COUNT_MASK 0xFFFFFFFF
+
int enable_events;
static char *policyname(int policy);
@@ -143,6 +150,7 @@ struct thread_param {
int cpu;
int node;
int tnum;
+ int msr_fd;
};
/* Struct for statistics */
@@ -154,6 +162,7 @@ struct thread_stat {
long act;
double avg;
long *values;
+ long *smis;
long *hist_array;
long *outliers;
pthread_t thread;
@@ -164,6 +173,7 @@ struct thread_stat {
long cycleofmax;
long hist_overflow;
long num_outliers;
+ unsigned long smi_count;
};
static pthread_mutex_t trigger_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -212,6 +222,12 @@ static pthread_t fifo_threadid;
static int laptop = 0;
static int use_histfile = 0;
+#ifdef ARCH_HAS_SMI_COUNTER
+static int smi = 0;
+#else
+#define smi 0
+#endif
+
static pthread_cond_t refresh_on_max_cond = PTHREAD_COND_INITIALIZER;
static pthread_mutex_t refresh_on_max_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -772,6 +788,125 @@ try_again:
return err;
}
+#ifdef ARCH_HAS_SMI_COUNTER
+static int open_msr_file(int cpu)
+{
+ int fd;
+ char pathname[32];
+
+ /* SMI needs thread affinity */
+ sprintf(pathname, "/dev/cpu/%d/msr", cpu);
+ fd = open(pathname, O_RDONLY);
+ if (fd < 0)
+ warn("%s open failed, try chown or chmod +r "
+ "/dev/cpu/*/msr, or run as root\n", pathname);
+
+ return fd;
+}
+
+static int get_msr(int fd, off_t offset, unsigned long long *msr)
+{
+ ssize_t retval;
+
+ retval = pread(fd, msr, sizeof *msr, offset);
+
+ if (retval != sizeof *msr)
+ return 1;
+
+ return 0;
+}
+
+static int get_smi_counter(int fd, unsigned long *counter)
+{
+ int retval;
+ unsigned long long msr;
+
+ retval = get_msr(fd, MSR_SMI_COUNT, &msr);
+ if (retval)
+ return retval;
+
+ *counter = (unsigned long) (msr & MSR_SMI_COUNT_MASK);
+
+ return 0;
+}
+
+#include <cpuid.h>
+
+/* Based on turbostat's check */
+static int has_smi_counter(void)
+{
+ unsigned int ebx, ecx, edx, max_level;
+ unsigned int fms, family, model;
+
+ fms = family = model = ebx = ecx = edx = 0;
+
+ __get_cpuid(0, &max_level, &ebx, &ecx, &edx);
+
+ /* check genuine intel */
+ if (!(ebx == 0x756e6547 && edx == 0x49656e69 && ecx == 0x6c65746e))
+ return 0;
+
+ __get_cpuid(1, &fms, &ebx, &ecx, &edx);
+ family = (fms >> 8) & 0xf;
+
+ if (family != 6)
+ return 0;
+
+ /* no MSR */
+ if (!(edx & (1 << 5)))
+ return 0;
+
+ model = (((fms >> 16) & 0xf) << 4) + ((fms >> 4) & 0xf);
+
+ switch (model) {
+ case 0x1A: /* Core i7, Xeon 5500 series - Bloomfield, Gainstown NHM-EP */
+ case 0x1E: /* Core i7 and i5 Processor - Clarksfield, Lynnfield, Jasper Forest */
+ case 0x1F: /* Core i7 and i5 Processor - Nehalem */
+ case 0x25: /* Westmere Client - Clarkdale, Arrandale */
+ case 0x2C: /* Westmere EP - Gulftown */
+ case 0x2E: /* Nehalem-EX Xeon - Beckton */
+ case 0x2F: /* Westmere-EX Xeon - Eagleton */
+ case 0x2A: /* SNB */
+ case 0x2D: /* SNB Xeon */
+ case 0x3A: /* IVB */
+ case 0x3E: /* IVB Xeon */
+ case 0x3C: /* HSW */
+ case 0x3F: /* HSX */
+ case 0x45: /* HSW */
+ case 0x46: /* HSW */
+ case 0x3D: /* BDW */
+ case 0x47: /* BDW */
+ case 0x4F: /* BDX */
+ case 0x56: /* BDX-DE */
+ case 0x4E: /* SKL */
+ case 0x5E: /* SKL */
+ case 0x37: /* BYT */
+ case 0x4D: /* AVN */
+ case 0x4C: /* AMT */
+ case 0x57: /* PHI */
+ break;
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+#else
+static int open_msr_file(int cpu)
+{
+ return -1;
+}
+
+static int get_smi_counter(int fd, unsigned long *counter)
+{
+ return 1;
+}
+static int has_smi_counter(void)
+{
+ return 0;
+}
+#endif
+
/*
* timer thread
*
@@ -798,6 +933,7 @@ static void *timerthread(void *param)
int stopped = 0;
cpu_set_t mask;
pthread_t thread;
+ unsigned long smi_now, smi_old;
/* if we're running in numa mode, set our memory node */
if (par->node != -1)
@@ -835,6 +971,17 @@ static void *timerthread(void *param)
fatal("timerthread%d: failed to set priority to %d\n",
par->cpu, par->prio);
+ if(smi) {
+ par->msr_fd = open_msr_file(par->cpu);
+ if (par->msr_fd < 0)
+ fatal("Could not open MSR interface, errno: %d\n",
+ errno);
+ /* get current smi count to use as base value */
+ if (get_smi_counter(par->msr_fd, &smi_old))
+ fatal("Could not read SMI counter, errno: %d\n",
+ par->cpu, errno);
+ }
+
/* Get current time */
if (aligned || secaligned) {
pthread_barrier_wait(&globalt_barr);
@@ -892,6 +1039,7 @@ static void *timerthread(void *param)
while (!shutdown) {
uint64_t diff;
+ unsigned long diff_smi = 0;
int sigs, ret;
/* Wait for next period */
@@ -957,6 +1105,17 @@ static void *timerthread(void *param)
goto out;
}
+ if (smi) {
+ if (get_smi_counter(par->msr_fd, &smi_now)) {
+ warn("Could not read SMI counter, errno: %d\n",
+ par->cpu, errno);
+ goto out;
+ }
+ diff_smi = smi_now - smi_old;
+ stat->smi_count += diff_smi;
+ smi_old = smi_now;
+ }
+
if (use_nsecs)
diff = calcdiff_ns(now, next);
else
@@ -974,6 +1133,7 @@ static void *timerthread(void *param)
trigger_update(par, diff, calctime(now));
}
+
if (duration && (calcdiff(now, stop) >= 0))
shutdown++;
@@ -991,8 +1151,11 @@ static void *timerthread(void *param)
}
stat->act = diff;
- if (par->bufmsk)
+ if (par->bufmsk) {
stat->values[stat->cycles & par->bufmsk] = diff;
+ if (smi)
+ stat->smis[stat->cycles & par->bufmsk] = diff_smi;
+ }
/* Update the histogram */
if (histogram) {
@@ -1038,10 +1201,12 @@ out:
setitimer(ITIMER_REAL, &itimer, NULL);
}
+ /* close msr file */
+ if (smi)
+ close(par->msr_fd);
/* switch to normal */
schedp.sched_priority = 0;
sched_setscheduler(0, SCHED_OTHER, &schedp);
-
stat->threadstarted = -1;
return NULL;
@@ -1126,6 +1291,9 @@ static void display_help(int error)
" --spike=trigger record all spikes > trigger\n"
" --spike-nodes these are the number of spikes we can record\n"
" the default is 1024 if not specified\n"
+#ifdef ARCH_HAS_SMI_COUNTER
+ " --smi Enable SMI counting\n"
+#endif
"-t --threads one thread per available processor\n"
"-t [NUM] --threads=NUM number of threads:\n"
" without NUM, threads = max_cpus\n"
@@ -1220,7 +1388,6 @@ static void parse_cpumask(const char *option, const int max_cpus)
}
}
-
static void handlepolicy(char *polname)
{
if (strncasecmp(polname, "other", 5) == 0)
@@ -1272,7 +1439,7 @@ enum option_values {
OPT_SYSTEM, OPT_SMP, OPT_THREADS, OPT_TRACER, OPT_TRIGGER,
OPT_TRIGGER_NODES, OPT_UNBUFFERED, OPT_NUMA, OPT_VERBOSE, OPT_WAKEUP,
OPT_WAKEUPRT, OPT_DBGCYCLIC, OPT_POLICY, OPT_HELP, OPT_NUMOPTS,
- OPT_ALIGNED, OPT_SECALIGNED, OPT_LAPTOP,
+ OPT_ALIGNED, OPT_SECALIGNED, OPT_LAPTOP, OPT_SMI,
};
/* Process commandline options */
@@ -1322,6 +1489,7 @@ static void process_options (int argc, char *argv[], int max_cpus)
{"resolution", no_argument, NULL, OPT_RESOLUTION },
{"secaligned", optional_argument, NULL, OPT_SECALIGNED },
{"system", no_argument, NULL, OPT_SYSTEM },
+ {"smi", no_argument, NULL, OPT_SMI },
{"smp", no_argument, NULL, OPT_SMP },
{"spike", required_argument, NULL, OPT_TRIGGER },
{"spike-nodes", required_argument, NULL, OPT_TRIGGER_NODES },
@@ -1560,6 +1728,13 @@ static void process_options (int argc, char *argv[], int max_cpus)
ct_debug = 1; break;
case OPT_LAPTOP:
laptop = 1; break;
+ case OPT_SMI:
+#ifdef ARCH_HAS_SMI_COUNTER
+ smi = 1;
+#else
+ fatal("--smi is not available on your arch\n");
+#endif
+ break;
}
}
@@ -1571,6 +1746,15 @@ static void process_options (int argc, char *argv[], int max_cpus)
}
}
+ if (smi) {
+ if (setaffinity == AFFINITY_UNSPECIFIED)
+ fatal("SMI counter relies on thread affinity\n");
+
+ if (!has_smi_counter())
+ fatal("SMI counter is not supported "
+ "on this processor\n");
+ }
+
if (tracelimit)
fileprefix = procfileprefix;
@@ -1810,27 +1994,44 @@ static void print_stat(FILE *fp, struct thread_param *par, int index, int verbos
char *fmt;
if (use_nsecs)
fmt = "T:%2d (%5d) P:%2d I:%ld C:%7lu "
- "Min:%7ld Act:%8ld Avg:%8ld Max:%8ld\n";
+ "Min:%7ld Act:%8ld Avg:%8ld Max:%8ld";
else
fmt = "T:%2d (%5d) P:%2d I:%ld C:%7lu "
- "Min:%7ld Act:%5ld Avg:%5ld Max:%8ld\n";
+ "Min:%7ld Act:%5ld Avg:%5ld Max:%8ld";
+
fprintf(fp, fmt, index, stat->tid, par->prio,
- par->interval, stat->cycles, stat->min, stat->act,
- stat->cycles ?
+ par->interval, stat->cycles, stat->min,
+ stat->act, stat->cycles ?
(long)(stat->avg/stat->cycles) : 0, stat->max);
+
+ if (smi)
+ fprintf(fp," SMI:%8ld", stat->smi_count);
+
+ fprintf(fp, "\n");
}
} else {
while (stat->cycles != stat->cyclesread) {
+ unsigned long diff_smi;
long diff = stat->values
[stat->cyclesread & par->bufmsk];
+ if (smi)
+ diff_smi = stat->smis
+ [stat->cyclesread & par->bufmsk];
+
if (diff > stat->redmax) {
stat->redmax = diff;
stat->cycleofmax = stat->cyclesread;
}
if (++stat->reduce == oscope_reduction) {
- fprintf(fp, "%8d:%8lu:%8ld\n", index,
- stat->cycleofmax, stat->redmax);
+ if (!smi)
+ fprintf(fp, "%8d:%8lu:%8ld\n", index,
+ stat->cycleofmax, stat->redmax);
+ else
+ fprintf(fp, "%8d:%8lu:%8ld%8ld\n",
+ index, stat->cycleofmax,
+ stat->redmax, diff_smi);
+
stat->reduce = 0;
stat->redmax = 0;
}
@@ -2154,6 +2355,13 @@ int main(int argc, char **argv)
goto outall;
memset(stat->values, 0, bufsize);
par->bufmsk = VALBUF_SIZE - 1;
+ if (smi) {
+ int bufsize = VALBUF_SIZE * sizeof(long);
+ stat->smis = threadalloc(bufsize, node);
+ if (!stat->smis)
+ goto outall;
+ memset(stat->smis, 0, bufsize);
+ }
}
par->prio = priority;
@@ -2192,6 +2400,7 @@ int main(int argc, char **argv)
stat->max = 0;
stat->avg = 0.0;
stat->threadstarted = 1;
+ stat->smi_count = 0;
status = pthread_create(&stat->thread, &attr, timerthread, par);
if (status)
fatal("failed to create thread %d: %s\n", i, strerror(status));
--
2.5.0
--
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