Description of problem: automount daemon is waking the system up every second, even when it's not in use at all! This is eating unneeded power / battery also, the following comment is *wrong* and actually increases power usage for no good reason: /* We often start several automounters at the same time. Add some randomness so we don't all expire at the same time. */ please make all timers fire at the same time instead!
(In reply to comment #0) > Description of problem: > > > automount daemon is waking the system up every second, even when it's not in use > at all! This is eating unneeded power / battery Some supporting evidence would be useful and is actually really needed. > > also, the following comment is *wrong* and actually increases power usage for no > good reason: > /* We often start several automounters at the same time. Add some > randomness so we don't all expire at the same time. */ > > please make all timers fire at the same time instead! Why? Some justification would be useful here as well since your view of what's actually happening here may not be what you think. Ian
curiously after a few reboots a strace no longer shows this behavior. WEIRD
(In reply to comment #2) > curiously after a few reboots a strace no longer shows this behavior. WEIRD > Perhaps the real culprit is behaving. Changing DEFAULT_LOGGING="none" to DEFAULT_LOGGING="debug" and telling syslog to send daemon.debug to somewhere useful will log the pid of processes requesting mounts and show when autofs expire events actually occur. Ian
Is this bug supposed to be in NEEDINFO? Arjan, how were you determining that autofs wakes up? With a simple strace of the automount pid? Is that going to be accurate given autofs is threaded?
(In reply to comment #4) > Is this bug supposed to be in NEEDINFO? Arjan, how were you determining that > autofs wakes up? With a simple strace of the automount pid? Is that going to > be accurate given autofs is threaded? No response. Closing as NOTABUG. Arjan, please re-open if this is still an issue with the latest autofs and mlocate packages. Ian
powertop shows constantly 1 wake up every second for automount. Is there something we can do to solve this? I'm using latest Rawhide as of today.
(In reply to comment #6) > powertop shows constantly 1 wake up every second for automount. Is there > something we can do to solve this? I'm using latest Rawhide as of today. Do you use autofs? If not, the simple answer is don't start it. If you are using autofs, then there is one potential optimization. We could disable the alarm when no file systems are mounted.
You are right, I thought I needed it but I don't so I disabled it. Curiously enough the wakeups went down from 20 to 16 per second even when powertop showed that automount was causing just one wps. Cheers.