Eclipse CPU usage 100 open XML

My Eclipse CPU usage grows to 100% after I try to open XML file.

Eclipse probably ended up with little available memory. Following setup solved my problem.
Open eclipse.ini from Eclipse installation dir. Change all memory variables to sufficient values, check especially following items:
--launcher.XXMaxPermSize 256M
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms100M
-Xmx512M
Start eclipse with additional parameter:
eclipse.exe ... -vmargs -Xmx256M
You can also start Eclipse in its own VM:
eclipse.exe -vm "C:\Program Files\Java\jdk1.5.0_22\bin\javaw.exe"


Later, dmatej sw suggested more complete arg list:

-vmargs
...
-Duser.name=...
-XX:PermSize=256m
-XX:MaxPermSize=256m
-Xmn128m
-Xms256m

-Xmx768m