perf tools: Add test for converting perf time to/from TSC
authorAdrian Hunter <adrian.hunter@intel.com>
Fri, 28 Jun 2013 13:22:19 +0000 (16:22 +0300)
committerIngo Molnar <mingo@kernel.org>
Tue, 23 Jul 2013 10:17:59 +0000 (12:17 +0200)
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: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter 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.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
tools/perf/Makefile
tools/perf/arch/x86/Makefile
tools/perf/arch/x86/util/tsc.c [new file with mode: 0644]
tools/perf/arch/x86/util/tsc.h [new file with mode: 0644]
tools/perf/tests/builtin-test.c
tools/perf/tests/perf-time-to-tsc.c [new file with mode: 0644]
tools/perf/tests/tests.h

index 024680b23ddc323701699f452e17432d2c68c7ed..bfd12d02a304687872e282c235f98b793d8424a6 100644 (file)
@@ -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
index 815841c04eb2f9b6db3ebeb3692711559d74e655..8801fe02f206a93a97d7f7cc8a56094dffa1d05c 100644 (file)
@@ -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
diff --git a/tools/perf/arch/x86/util/tsc.c b/tools/perf/arch/x86/util/tsc.c
new file mode 100644 (file)
index 0000000..f111744
--- /dev/null
@@ -0,0 +1,59 @@
+#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;
+}
diff --git a/tools/perf/arch/x86/util/tsc.h b/tools/perf/arch/x86/util/tsc.h
new file mode 100644 (file)
index 0000000..a24dec8
--- /dev/null
@@ -0,0 +1,20 @@
+#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__ */
index 35b45f1466b52e1ac934c99ccc1af1447539ce30..b7b4049fabbb33740cb0c99ceb867194b8c0c354 100644 (file)
@@ -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,
        },
diff --git a/tools/perf/tests/perf-time-to-tsc.c b/tools/perf/tests/perf-time-to-tsc.c
new file mode 100644 (file)
index 0000000..0ab61b1
--- /dev/null
@@ -0,0 +1,177 @@
+#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;
+}
index 07a92f9c67123d578c8069a3a24f8090b6cd9ce1..d22202aa16e93078a8dc769b94b0af9bbde4fc60 100644 (file)
@@ -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 */