diff options
| -rw-r--r-- | iowatcher/tracers.c | 129 | ||||
| -rw-r--r-- | iowatcher/tracers.h | 2 |
2 files changed, 55 insertions, 76 deletions
diff --git a/iowatcher/tracers.c b/iowatcher/tracers.c index 4844deb..6ecf24c 100644 --- a/iowatcher/tracers.c +++ b/iowatcher/tracers.c @@ -46,26 +46,12 @@ static char line[1024]; static pid_t blktrace_pid = 0; static pid_t mpstat_pid = 0; -char *blktrace_args[17 + MAX_DEVICES_PER_TRACE * 2] = { - "blktrace", - "-b", "8192", - "-a", "queue", - "-a", "complete", - "-a", "issue", - "-a", "notify", - "-D", ".", - NULL, -}; - char *mpstat_args[] = { "mpstat", "-P", "ALL", "1", NULL, }; -#define DEST_DIR_INDEX 12 -#define LAST_ARG 13 - int stop_tracer(pid_t *tracer_pid) { int ret; @@ -90,91 +76,82 @@ int stop_tracer(pid_t *tracer_pid) return 0; } - -void stop_all_tracers(void) +static void sig_handler_for_quit(int val) { - stop_tracer(&blktrace_pid); + fprintf(stderr, "Received signal %d. Terminating tracers.\n", val); + if (blktrace_pid) { + wait_program(blktrace_pid, "blktrace", SIGTERM); + blktrace_pid = 0; + } stop_tracer(&mpstat_pid); } -void sig_handler_for_quit(int val) -{ - fprintf(stderr, "iowatcher exiting with %d, stopping tracers\n", val); - stop_all_tracers(); -} - - int start_blktrace(char **devices, int num_devices, char *trace_name, char *dest) { - pid_t pid; int ret; - char **arg = blktrace_args; int i; - int arg_index; + char *argv[15 + MAX_DEVICES_PER_TRACE * 2]; + int argc = 0; - fprintf(stderr, "running blktrace"); if (!trace_name) trace_name = "trace"; + if (!dest) + dest = "."; + + argv[argc++] = "blktrace"; + argv[argc++] = "-b"; + argv[argc++] = "8192"; + argv[argc++] = "-a"; + argv[argc++] = "queue"; + argv[argc++] = "-a"; + argv[argc++] = "complete"; + argv[argc++] = "-a"; + argv[argc++] = "issue"; + argv[argc++] = "-a"; + argv[argc++] = "notify"; - arg_index = LAST_ARG; - for (i = 0; i < num_devices; i++) { - blktrace_args[arg_index++] = "-d"; - blktrace_args[arg_index++] = devices[i]; - } - - /* - * single device traces use -o and are put into - * the dest dir if provided - */ if (num_devices == 1) { - blktrace_args[arg_index++] = "-o"; - blktrace_args[arg_index++] = trace_name; - if (dest) - blktrace_args[DEST_DIR_INDEX] = dest; + argv[argc++] = "-o"; + argv[argc++] = trace_name; } else { - /* - * multi device traces are put into a dest - * dir based on the trace name - */ - blktrace_args[DEST_DIR_INDEX] = trace_name; + /* Multiple devices output to a directory named trace_name */ + dest = trace_name; } + argv[argc++] = "-D"; + argv[argc++] = dest; - blktrace_args[arg_index] = NULL; - - while(*arg) { - fprintf(stderr, " %s", *arg); - arg++; - } - fprintf(stderr, "\n"); - - - pid = fork(); - if (pid == 0) { - ret = execvp("blktrace", blktrace_args); - if (ret) { - fprintf(stderr, "failed to exec blktrace error %s\n", strerror(errno)); - exit(errno); - } - - } else { - blktrace_pid = pid; - signal(SIGTERM, sig_handler_for_quit); - signal(SIGINT, sig_handler_for_quit); + for (i = 0; i < num_devices; i++) { + argv[argc++] = "-d"; + argv[argc++] = devices[i]; } - return 0; + argv[argc] = NULL; + signal(SIGTERM, sig_handler_for_quit); + signal(SIGINT, sig_handler_for_quit); + ret = run_program(argc, argv, 0, &blktrace_pid); + return ret; } -int wait_program(pid_t pid, const char *pname) +int wait_program(pid_t pid, const char *pname, int sig) { int status; int ret = 0; + if (sig) { + ret = kill(pid, sig); + if (ret) { + fprintf(stderr, "Failed to send signal %d to %s (%lu): %s\n", + sig, pname, (long)pid, strerror(errno)); + return ret; + } + fprintf(stderr, "Kill (%d): %s (%ld)\n", sig, pname, (long)pid); + } + waitpid(pid, &status, 0); if (WIFEXITED(status)) { ret = WEXITSTATUS(status); if (ret == 127) /* spawnp failed after forking */ fprintf(stderr, "Failed to run '%s'\n", pname); - } else if (WIFSIGNALED(status)) { + } else if (WIFSIGNALED(status) && sig && WTERMSIG(status) != sig) { fprintf(stderr, "'%s' killed by signal %d\n", pname, WTERMSIG(status)); ret = -1; } @@ -196,7 +173,7 @@ int run_program(int argc, char **argv, int wait, pid_t *pid) if (err != 0) { fprintf(stderr, "Could not run '%s': %s\n", argv[0], strerror(err)); } else if (wait) { - err = wait_program(_pid, argv[0]); + err = wait_program(_pid, argv[0], 0); } else if (!pid) { fprintf(stderr, "Warning: %s (%ld): Not saving pid and not waiting for it.\n", argv[0], (long)_pid); @@ -208,13 +185,15 @@ int run_program(int argc, char **argv, int wait, pid_t *pid) int wait_for_tracers(void) { - int status = 0; - stop_all_tracers(); if (blktrace_pid != 0) { - waitpid(blktrace_pid, &status, WUNTRACED); + int err = wait_program(blktrace_pid, "blktrace", SIGINT); + if (err) + exit(1); blktrace_pid = 0; } if (mpstat_pid != 0) { + int status = 0; + stop_tracer(&mpstat_pid); waitpid(mpstat_pid, &status, WUNTRACED); mpstat_pid = 0; } diff --git a/iowatcher/tracers.h b/iowatcher/tracers.h index ed57f5d..77c31a6 100644 --- a/iowatcher/tracers.h +++ b/iowatcher/tracers.h @@ -18,7 +18,7 @@ #ifndef __IOWATCH_TRACERS #define __IOWATCH_TRACERS int run_program(int argc, char **argv, int wait, pid_t *pid); -int wait_program(pid_t pid, const char *pname); +int wait_program(pid_t pid, const char *pname, int signal); int stop_blktrace(void); int start_blktrace(char **devices, int num_devices, char *trace_name, char *dest); int start_mpstat(char *trace_name); |