Commit 3bd5a5fc authored by Adrian Hunter's avatar Adrian Hunter Committed by Ingo Molnar

perf tools: Add test for converting perf time to/from TSC

The test uses the newly added cap_usr_time_zero and time_zero of
perf_event_mmap_page.  TSC from rdtsc is compared with the time
from 2 perf events.  The test passes if the calculated times are
all in the correct order.
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1372425741-1676-4-git-send-email-adrian.hunter@intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent c73deb6a
......@@ -389,6 +389,9 @@ LIB_OBJS += $(OUTPUT)tests/bp_signal.o
LIB_OBJS += $(OUTPUT)tests/bp_signal_overflow.o
LIB_OBJS += $(OUTPUT)tests/task-exit.o
LIB_OBJS += $(OUTPUT)tests/sw-clock.o
ifeq ($(ARCH),x86)
LIB_OBJS += $(OUTPUT)tests/perf-time-to-tsc.o
endif
BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
BUILTIN_OBJS += $(OUTPUT)builtin-bench.o
......
......@@ -6,3 +6,5 @@ ifndef NO_LIBUNWIND
LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind.o
endif
LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/header.o
LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/tsc.o
LIB_H += arch/$(ARCH)/util/tsc.h
#include <stdbool.h>
#include <errno.h>
#include <linux/perf_event.h>
#include "../../perf.h"
#include "../../util/types.h"
#include "../../util/debug.h"
#include "tsc.h"
u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc)
{
u64 time, quot, rem;
time = ns - tc->time_zero;
quot = time / tc->time_mult;
rem = time % tc->time_mult;
return (quot << tc->time_shift) +
(rem << tc->time_shift) / tc->time_mult;
}
u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc)
{
u64 quot, rem;
quot = cyc >> tc->time_shift;
rem = cyc & ((1 << tc->time_shift) - 1);
return tc->time_zero + quot * tc->time_mult +
((rem * tc->time_mult) >> tc->time_shift);
}
int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,
struct perf_tsc_conversion *tc)
{
bool cap_usr_time_zero;
u32 seq;
int i = 0;
while (1) {
seq = pc->lock;
rmb();
tc->time_mult = pc->time_mult;
tc->time_shift = pc->time_shift;
tc->time_zero = pc->time_zero;
cap_usr_time_zero = pc->cap_usr_time_zero;
rmb();
if (pc->lock == seq && !(seq & 1))
break;
if (++i > 10000) {
pr_debug("failed to get perf_event_mmap_page lock\n");
return -EINVAL;
}
}
if (!cap_usr_time_zero)
return -EOPNOTSUPP;
return 0;
}
#ifndef TOOLS_PERF_ARCH_X86_UTIL_TSC_H__
#define TOOLS_PERF_ARCH_X86_UTIL_TSC_H__
#include "../../util/types.h"
struct perf_tsc_conversion {
u16 time_shift;
u32 time_mult;
u64 time_zero;
};
struct perf_event_mmap_page;
int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,
struct perf_tsc_conversion *tc);
u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc);
u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc);
#endif /* TOOLS_PERF_ARCH_X86_UTIL_TSC_H__ */
......@@ -93,6 +93,12 @@ static struct test {
.desc = "Test software clock events have valid period values",
.func = test__sw_clock_freq,
},
#if defined(__x86_64__) || defined(__i386__)
{
.desc = "Test converting perf time to TSC",
.func = test__perf_time_to_tsc,
},
#endif
{
.func = NULL,
},
......
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <inttypes.h>
#include <sys/prctl.h>
#include "parse-events.h"
#include "evlist.h"
#include "evsel.h"
#include "thread_map.h"
#include "cpumap.h"
#include "tests.h"
#include "../arch/x86/util/tsc.h"
#define CHECK__(x) { \
while ((x) < 0) { \
pr_debug(#x " failed!\n"); \
goto out_err; \
} \
}
#define CHECK_NOT_NULL__(x) { \
while ((x) == NULL) { \
pr_debug(#x " failed!\n"); \
goto out_err; \
} \
}
static u64 rdtsc(void)
{
unsigned int low, high;
asm volatile("rdtsc" : "=a" (low), "=d" (high));
return low | ((u64)high) << 32;
}
/**
* test__perf_time_to_tsc - test converting perf time to TSC.
*
* This function implements a test that checks that the conversion of perf time
* to and from TSC is consistent with the order of events. If the test passes
* %0 is returned, otherwise %-1 is returned. If TSC conversion is not
* supported then then the test passes but " (not supported)" is printed.
*/
int test__perf_time_to_tsc(void)
{
struct perf_record_opts opts = {
.mmap_pages = UINT_MAX,
.user_freq = UINT_MAX,
.user_interval = ULLONG_MAX,
.freq = 4000,
.target = {
.uses_mmap = true,
},
.sample_time = true,
};
struct thread_map *threads = NULL;
struct cpu_map *cpus = NULL;
struct perf_evlist *evlist = NULL;
struct perf_evsel *evsel = NULL;
int err = -1, ret, i;
const char *comm1, *comm2;
struct perf_tsc_conversion tc;
struct perf_event_mmap_page *pc;
union perf_event *event;
u64 test_tsc, comm1_tsc, comm2_tsc;
u64 test_time, comm1_time = 0, comm2_time = 0;
threads = thread_map__new(-1, getpid(), UINT_MAX);
CHECK_NOT_NULL__(threads);
cpus = cpu_map__new(NULL);
CHECK_NOT_NULL__(cpus);
evlist = perf_evlist__new();
CHECK_NOT_NULL__(evlist);
perf_evlist__set_maps(evlist, cpus, threads);
CHECK__(parse_events(evlist, "cycles:u"));
perf_evlist__config(evlist, &opts);
evsel = perf_evlist__first(evlist);
evsel->attr.comm = 1;
evsel->attr.disabled = 1;
evsel->attr.enable_on_exec = 0;
CHECK__(perf_evlist__open(evlist));
CHECK__(perf_evlist__mmap(evlist, UINT_MAX, false));
pc = evlist->mmap[0].base;
ret = perf_read_tsc_conversion(pc, &tc);
if (ret) {
if (ret == -EOPNOTSUPP) {
fprintf(stderr, " (not supported)");
return 0;
}
goto out_err;
}
perf_evlist__enable(evlist);
comm1 = "Test COMM 1";
CHECK__(prctl(PR_SET_NAME, (unsigned long)comm1, 0, 0, 0));
test_tsc = rdtsc();
comm2 = "Test COMM 2";
CHECK__(prctl(PR_SET_NAME, (unsigned long)comm2, 0, 0, 0));
perf_evlist__disable(evlist);
for (i = 0; i < evlist->nr_mmaps; i++) {
while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
struct perf_sample sample;
if (event->header.type != PERF_RECORD_COMM ||
(pid_t)event->comm.pid != getpid() ||
(pid_t)event->comm.tid != getpid())
continue;
if (strcmp(event->comm.comm, comm1) == 0) {
CHECK__(perf_evsel__parse_sample(evsel, event,
&sample));
comm1_time = sample.time;
}
if (strcmp(event->comm.comm, comm2) == 0) {
CHECK__(perf_evsel__parse_sample(evsel, event,
&sample));
comm2_time = sample.time;
}
}
}
if (!comm1_time || !comm2_time)
goto out_err;
test_time = tsc_to_perf_time(test_tsc, &tc);
comm1_tsc = perf_time_to_tsc(comm1_time, &tc);
comm2_tsc = perf_time_to_tsc(comm2_time, &tc);
pr_debug("1st event perf time %"PRIu64" tsc %"PRIu64"\n",
comm1_time, comm1_tsc);
pr_debug("rdtsc time %"PRIu64" tsc %"PRIu64"\n",
test_time, test_tsc);
pr_debug("2nd event perf time %"PRIu64" tsc %"PRIu64"\n",
comm2_time, comm2_tsc);
if (test_time <= comm1_time ||
test_time >= comm2_time)
goto out_err;
if (test_tsc <= comm1_tsc ||
test_tsc >= comm2_tsc)
goto out_err;
err = 0;
out_err:
if (evlist) {
perf_evlist__disable(evlist);
perf_evlist__munmap(evlist);
perf_evlist__close(evlist);
perf_evlist__delete(evlist);
}
if (cpus)
cpu_map__delete(cpus);
if (threads)
thread_map__delete(threads);
return err;
}
......@@ -35,5 +35,6 @@ int test__bp_signal(void);
int test__bp_signal_overflow(void);
int test__task_exit(void);
int test__sw_clock_freq(void);
int test__perf_time_to_tsc(void);
#endif /* TESTS_H */
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