Bugzilla – Bug 15794
Squeezebox Server is hogging CPU time after playlist is completed, but only if Web GUI open
Last modified: 2010-04-12 10:18:09 UTC
When the Squeezebox Server Web GUI ("Web Control") is open, and a playlist completes, then the CPU usage consumed by the Squeezebox Server (processes SQUEEZ~3.EXE and mysqld.exe) suddenly jumps from about 2% CPU time each, to a varying load, averaging about 25% CPU time, despite the Squeezebox Server has nothing to do!!! Squeezebox Server process "idle" CPU usage: SQUEEZ~3.EXE = 0-1% mysqld.exe = mostly 0%, but every 15s it suddenly briefly spikes to 20-35%. Squeezebox Server process CPU usage when playing the playlist: = about the same as idle usage. Squeezebox Server process continuous CPU usage after playlist has completed (with Web GUI open): SQUEEZ~3.EXE = 5-20% mysqld.exe = 5-30% Note that this higher CPU usage continues forever after the playlist is completed, but goes back to normal if a new playlist is started, or if the Web GUI is terminated, or if the playlist is cleared. This causes my (fairly old) laptop PC to become sluggish, when I also use it for other purposes. Note: This only happens when the Web GUI is running when the playlist completes. So, something is continuing to use extra CPU time after the playlist completes. Note: This happens with Squeezebox Server v.7.4.2, but it also happened with the old SqueezeCenter v.7.3.3.
I think there was some other activity going on when I took the CPU load figures last time, so I did those again, to get a cleaner picture: Idle, with Web Gui open (before any use): mysqld.exe: 0% SQUEEZ~3.EXE: 0-2% While playing playlist, with Web GUI open: mysqld.exe: 0% SQUEEZ~3.EXE: 0-3% After completing playlist, with Web GUI still open: mysqld.exe: 5-8% SQUEEZ~3.EXE: ~13% (10-20%) When the Web GUI window is in focus, then iexplorer.exe additionally uses approx 9-23% This gives a cleaner picture - when the playlist completes and the Web GUI is sill open, then the CPU usage for both mysqld.exe and SQUEEZ~3.EXE suddenly jump up, dramatically, and remains high until a either new playlist is started, the Web GUI is terminated, or the playlist is cleared.
What's happening is that the web UI is starting to query for updates every second (or more). This shouldn't happen.
Fixed in 7.6 as of r30539