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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2011-11-21 14:42:47 +0100
committerIngo Molnar <mingo@elte.hu>2011-12-21 12:21:42 +0100
commit08aa0d1f376e9b966568316bd2019b3c1274d885 (patch)
tree494c1ef502a8c9258a89a6a6c3d95c6137728e64 /tools/perf/builtin-test.c
parente3f3541c19c89a4daae39300defba68943301949 (diff)
perf tools: Add x86 RDPMC, RDTSC test
Implement a simple test for the self-monitoring data from the perf mmap data area control page: 6: x86 rdpmc test: 0: 6053 1: 60053 2: 600059 3: 6000059 4: 60000075 5: 600000247 Ok The counts are expected to increase monotonically - these are recovered via RDPMC, without calling into the kernel. It might be nice to add logic to automagically turn these numbers into OK/FAIL. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: Arun Sharma <asharma@fb.com> Link: http://lkml.kernel.org/n/tip-evf5yii88ljdgmaihccbxxw1@git.kernel.org [ various small improvements ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools/perf/builtin-test.c')
-rw-r--r--tools/perf/builtin-test.c177
1 files changed, 175 insertions, 2 deletions
diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index 2b9a7f497a20..439b5ed03e64 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -15,6 +15,8 @@
#include "util/thread_map.h"
#include "../../include/linux/hw_breakpoint.h"
+#include <sys/mman.h>
+
static int vmlinux_matches_kallsyms_filter(struct map *map __used, struct symbol *sym)
{
bool *visited = symbol__priv(sym);
@@ -1296,6 +1298,173 @@ out:
return (err < 0 || errs > 0) ? -1 : 0;
}
+
+#if defined(__x86_64__) || defined(__i386__)
+
+#define barrier() asm volatile("" ::: "memory")
+
+static u64 rdpmc(unsigned int counter)
+{
+ unsigned int low, high;
+
+ asm volatile("rdpmc" : "=a" (low), "=d" (high) : "c" (counter));
+
+ return low | ((u64)high) << 32;
+}
+
+static u64 rdtsc(void)
+{
+ unsigned int low, high;
+
+ asm volatile("rdtsc" : "=a" (low), "=d" (high));
+
+ return low | ((u64)high) << 32;
+}
+
+static u64 mmap_read_self(void *addr)
+{
+ struct perf_event_mmap_page *pc = addr;
+ u32 seq, idx, time_mult = 0, time_shift = 0;
+ u64 count, cyc = 0, time_offset = 0, enabled, running, delta;
+
+ do {
+ seq = pc->lock;
+ barrier();
+
+ enabled = pc->time_enabled;
+ running = pc->time_running;
+
+ if (enabled != running) {
+ cyc = rdtsc();
+ time_mult = pc->time_mult;
+ time_shift = pc->time_shift;
+ time_offset = pc->time_offset;
+ }
+
+ idx = pc->index;
+ count = pc->offset;
+ if (idx)
+ count += rdpmc(idx - 1);
+
+ barrier();
+ } while (pc->lock != seq);
+
+ if (enabled != running) {
+ u64 quot, rem;
+
+ quot = (cyc >> time_shift);
+ rem = cyc & ((1 << time_shift) - 1);
+ delta = time_offset + quot * time_mult +
+ ((rem * time_mult) >> time_shift);
+
+ enabled += delta;
+ if (idx)
+ running += delta;
+
+ quot = count / running;
+ rem = count % running;
+ count = quot * enabled + (rem * enabled) / running;
+ }
+
+ return count;
+}
+
+/*
+ * If the RDPMC instruction faults then signal this back to the test parent task:
+ */
+static void segfault_handler(int sig __used, siginfo_t *info __used, void *uc __used)
+{
+ exit(-1);
+}
+
+static int __test__rdpmc(void)
+{
+ long page_size = sysconf(_SC_PAGE_SIZE);
+ volatile int tmp = 0;
+ u64 i, loops = 1000;
+ int n;
+ int fd;
+ void *addr;
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_HARDWARE,
+ .config = PERF_COUNT_HW_INSTRUCTIONS,
+ .exclude_kernel = 1,
+ };
+ u64 delta_sum = 0;
+ struct sigaction sa;
+
+ sigfillset(&sa.sa_mask);
+ sa.sa_sigaction = segfault_handler;
+ sigaction(SIGSEGV, &sa, NULL);
+
+ fprintf(stderr, "\n\n");
+
+ fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
+ if (fd < 0) {
+ die("Error: sys_perf_event_open() syscall returned "
+ "with %d (%s)\n", fd, strerror(errno));
+ }
+
+ addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0);
+ if (addr == (void *)(-1)) {
+ die("Error: mmap() syscall returned "
+ "with (%s)\n", strerror(errno));
+ }
+
+ for (n = 0; n < 6; n++) {
+ u64 stamp, now, delta;
+
+ stamp = mmap_read_self(addr);
+
+ for (i = 0; i < loops; i++)
+ tmp++;
+
+ now = mmap_read_self(addr);
+ loops *= 10;
+
+ delta = now - stamp;
+ fprintf(stderr, "%14d: %14Lu\n", n, (long long)delta);
+
+ delta_sum += delta;
+ }
+
+ munmap(addr, page_size);
+ close(fd);
+
+ fprintf(stderr, " ");
+
+ if (!delta_sum)
+ return -1;
+
+ return 0;
+}
+
+static int test__rdpmc(void)
+{
+ int status = 0;
+ int wret = 0;
+ int ret;
+ int pid;
+
+ pid = fork();
+ if (pid < 0)
+ return -1;
+
+ if (!pid) {
+ ret = __test__rdpmc();
+
+ exit(ret);
+ }
+
+ wret = waitpid(pid, &status, 0);
+ if (wret < 0 || status)
+ return -1;
+
+ return 0;
+}
+
+#endif
+
static struct test {
const char *desc;
int (*func)(void);
@@ -1320,6 +1489,12 @@ static struct test {
.desc = "parse events tests",
.func = test__parse_events,
},
+#if defined(__x86_64__) || defined(__i386__)
+ {
+ .desc = "x86 rdpmc test",
+ .func = test__rdpmc,
+ },
+#endif
{
.desc = "Validate PERF_RECORD_* events & perf_sample fields",
.func = test__PERF_RECORD,
@@ -1412,7 +1587,5 @@ int cmd_test(int argc, const char **argv, const char *prefix __used)
if (symbol__init() < 0)
return -1;
- setup_pager();
-
return __cmd_test(argc, argv);
}