Bug 22005 - xscreensaver runs when monitor is powered down by DPMS
xscreensaver runs when monitor is powered down by DPMS
Product: Red Hat Linux
Classification: Retired
Component: xscreensaver (Show other bugs)
All Linux
low Severity low
: ---
: ---
Assigned To: Bill Nottingham
Depends On:
  Show dependency treegraph
Reported: 2000-12-09 14:11 EST by David Woodhouse
Modified: 2014-03-16 22:17 EDT (History)
1 user (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2000-12-09 14:11:06 EST
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)

  None (edit)
Description David Woodhouse 2000-12-09 14:11:04 EST
The xscreensaver man page says:

       Modern X servers contain support to power down the monitor
       after  an  idle  period.  If the monitor has powered down,
       then xscreensaver will notice this, and will not waste CPU
       by  drawing  graphics demos on a black screen.  An attempt
       will also be made to explicitly power the monitor back  up
       as soon as user activity is detected.

It lies. It still runs while X has put the monitor into standby. Taking an
xwd confirms that the module really is displaying - it's not just that the
check for DPMS is done in the submodules rather than the xscreensaver

passion /home/dwmw2 $ ps axf | (sleep 1 ; grep --after-context=1
 1311 ?        S      0:01 xscreensaver -no-splash -timeout 10 -nice 10
 3404 ?        SN     0:02  \_ penetrate -root
passion /home/dwmw2 $ xset q | grep --after-context=1 DPMS
DPMS (Energy Star):
  Standby: 0    Suspend: 0    Off: 1200
  DPMS is Enabled
  Monitor is Off
passion /home/dwmw2 $ 

On a desktop machine, this is harmless enough - aside from making me think
X had crashed because it was taking 99% CPU. On a laptop where we actually
want to conserve power, it's more important.

It shouldn't matter, but the X server is somewhere between 4.0.1e and
4.0.1f on SMP x86.
Comment 1 Bill Nottingham 2001-03-29 02:17:53 EST
This shouldn't happen anymore witn 3.29-1 or later, as xscreensaver
took over doing DPMS stuff...

Note You need to log in before you can comment on or make changes to this bug.