trace_waitpid() loop hogs one CPU during trace-cmd record. Add a delay there to slow down the loop, to reduce the CPU load.
Signed-off-by: Vincent Stehlé <[email protected]> Cc: Steven Rostedt <[email protected]> --- Changes since v1: - Use nanosleep and sleep_time from command line. trace-record.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/trace-record.c b/trace-record.c index 18e2e2d..a230fde 100644 --- a/trace-record.c +++ b/trace-record.c @@ -837,6 +837,7 @@ static pid_t trace_waitpid(enum trace_type type, pid_t pid, int *status, int opt struct timeval tv = { 1, 0 }; int ret; int profile = (type & TRACE_TYPE_PROFILE) == TRACE_TYPE_PROFILE; + struct timespec req; options |= WNOHANG; @@ -847,6 +848,11 @@ static pid_t trace_waitpid(enum trace_type type, pid_t pid, int *status, int opt if (type & TRACE_TYPE_STREAM) trace_stream_read(pids, recorder_threads, &tv, profile); + + req.tv_sec = sleep_time / 1000000; + req.tv_nsec = (sleep_time % 1000000) * 1000; + nanosleep(&req, NULL); + } while (1); } #ifndef NO_PTRACE -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
