Opened 14 years ago

Closed 14 years ago

Last modified 14 years ago

#3800 closed enhancement (invalid)

mythbackend and mythwelcome wakeup a lot

Reported by: anonymous Owned by: Isaac Richards
Priority: minor Milestone: unknown
Component: mythtv Version: 0.20-fixes
Severity: medium Keywords: wakeup idle loop sleep
Cc: Ticket locked: no


Running mythtv 0.20.1-161 (RPMs from ATrpms) on Fedora 7. Using powertop, I have found that on an idle system, mythwelcome and mythbackend wakeup very frequently from what appears to be polling loops with short sleeps. mythfrontend isn't running.

Here is some data from power top. The % gives you the % of total wakeups that process/event is responsible for, the number in parens is the number of wakeups per second that process/event is responsible for.

43.8% (170.4) mythwelcome : schedule_timeout (process_timeout)

26.3% (102.2) mythbackend : schedule_timeout (process_timeout)

19.5% ( 75.6) <interrupt> : ivtv0, nvidia

5.1% ( 20.0) mythbackend : futex_wait (hrtimer_wakeup)

0.9% ( 3.5) wmaker : schedule_timeout (process_timeout)

0.9% ( 3.4) X : do_setitimer (it_real_fn)

Reducing the number of wakeups will reduce power consumption slightly on all machines, but it is especially noticable on hardware which supports lower CPU C-states.

Change History (3)

comment:1 Changed 14 years ago by David Rees <drees76@…>

Hmm, I tried to enter my email address on the report, but it didn't take. This comment should include it now.

comment:2 Changed 14 years ago by danielk

Resolution: invalid
Status: newclosed

Enhancement ticket's need to have a patch attached, and this doesn't qualify as a defect. Thanks for collecting this data, if you post it to the developer mailing list it may trigger some discussion. MythWelcome? appears to waking up surprisingly often.

comment:3 Changed 14 years ago by drees76@…

Thanks. I did some additional research and found that this has already been discussed further ticket #3757.

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