diff options
Diffstat (limited to 'tools/perf/jvmti/jvmti_agent.c')
| -rw-r--r-- | tools/perf/jvmti/jvmti_agent.c | 43 |
1 files changed, 41 insertions, 2 deletions
diff --git a/tools/perf/jvmti/jvmti_agent.c b/tools/perf/jvmti/jvmti_agent.c index 6461e02ab940..3573f315f955 100644 --- a/tools/perf/jvmti/jvmti_agent.c +++ b/tools/perf/jvmti/jvmti_agent.c @@ -92,6 +92,22 @@ error: return ret; } +static int use_arch_timestamp; + +static inline uint64_t +get_arch_timestamp(void) +{ +#if defined(__i386__) || defined(__x86_64__) + unsigned int low, high; + + asm volatile("rdtsc" : "=a" (low), "=d" (high)); + + return low | ((uint64_t)high) << 32; +#else + return 0; +#endif +} + #define NSEC_PER_SEC 1000000000 static int perf_clk_id = CLOCK_MONOTONIC; @@ -107,6 +123,9 @@ perf_get_timestamp(void) struct timespec ts; int ret; + if (use_arch_timestamp) + return get_arch_timestamp(); + ret = clock_gettime(perf_clk_id, &ts); if (ret) return 0; @@ -203,6 +222,17 @@ perf_close_marker_file(void) munmap(marker_addr, pgsz); } +static void +init_arch_timestamp(void) +{ + char *str = getenv("JITDUMP_USE_ARCH_TIMESTAMP"); + + if (!str || !*str || !strcmp(str, "0")) + return; + + use_arch_timestamp = 1; +} + void *jvmti_open(void) { int pad_cnt; @@ -211,11 +241,17 @@ void *jvmti_open(void) int fd; FILE *fp; + init_arch_timestamp(); + /* * check if clockid is supported */ - if (!perf_get_timestamp()) - warnx("jvmti: kernel does not support %d clock id", perf_clk_id); + if (!perf_get_timestamp()) { + if (use_arch_timestamp) + warnx("jvmti: arch timestamp not supported"); + else + warnx("jvmti: kernel does not support %d clock id", perf_clk_id); + } memset(&header, 0, sizeof(header)); @@ -263,6 +299,9 @@ void *jvmti_open(void) header.timestamp = perf_get_timestamp(); + if (use_arch_timestamp) + header.flags |= JITDUMP_FLAGS_ARCH_TIMESTAMP; + if (!fwrite(&header, sizeof(header), 1, fp)) { warn("jvmti: cannot write dumpfile header"); goto error; |