On Mon, 2014-05-12 at 13:43 -0400, Dave Jones wrote:
> heh, I knew I'd forget something. Hopefully "cc'ing the trinity list"
> was the only thing this time around..
Hi Dave,
I gave this spin on a system of mine here.
I'm consistently ending up with a watchdog that is spinning using 100% cpu.
strace shows it spinning calling kill:
kill(17833, SIG_0) = -1 ESRCH (No such process)
kill(17833, SIG_0) = -1 ESRCH (No such process)
kill(17833, SIG_0) = -1 ESRCH (No such process)
kill(17833, SIG_0) = -1 ESRCH (No such process)
...
Which gdb agrees with:
(gdb) bt
#0 0x1001c790 in kill@plt ()
#1 0x10001984 in __check_main () at watchdog.c:158
#2 0x10010510 in check_main_alive () at watchdog.c:185
#3 watchdog () at watchdog.c:407
#4 init_watchdog () at watchdog.c:484
#5 0x10001d04 in main (argc=1, argv=<optimized out>) at trinity.c:128
It's looping around:
183 while (shm->mainpid != 0) {
(gdb) n
185 ret = __check_main();
(gdb)
186 if (ret == TRUE) {
(gdb)
183 while (shm->mainpid != 0) {
(gdb)
185 ret = __check_main();
(gdb)
186 if (ret == TRUE) {
(gdb)
183 while (shm->mainpid != 0) {
(gdb)
185 ret = __check_main();
(gdb)
186 if (ret == TRUE) {
shm->mainpid is 17833, which agrees with strace, and that process is indeed
no longer running.
We are bailing out of __check_main() before clearing shm->mainpid because we
see that we are already exiting.
if (ret == -1) {
/* Are we already exiting ? */
if (shm->exit_reason != STILL_RUNNING)
return FALSE;
/* No. Check what happened. */
if (errno == ESRCH) {
161 if (shm->exit_reason != STILL_RUNNING)
(gdb) print shm->exit_reason
$6 = EXIT_FORK_FAILURE
It looks like the only other place shm->mainpid is written is in
trinity.c:main(), which is dead. So we are stuck forever as far as I can tell.
The last thing in trinity.log is:
[main] couldn't create child! (Cannot allocate memory)
>From main.c:69:
output(0, "couldn't create child! (%s)\n", strerror(errn o));
shm->exit_reason = EXIT_FORK_FAILURE;
exit(EXIT_FAILURE);
So we exited directly and didn't let the code in main() clear shm->mainpid.
Not sure what the correct fix is. We could drop the check of shm->exit_reason
in __check_main(), but presumably that is there for a good reason.
cheers
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