Hi,

a few days ago I noticed that my Athlon 3000+ was relatively hot (49C) 
although it was completely idle. At that time I was running 2.6.3-mm3 with 
ACPI and IOAPIC-support enabled.

As I tried 2.6.3, the idle temperature was at normal 39C. So I did do some 
binary search with the -bk patches and found the patch that causes the high 
idle temperature. It is ChangeSet@1.1626 aka 8259-timer-ack-fix.patch.

A patch to revert that ChangeSet for 2.6.4-rc1-mm2 is attached.

Best regards
   Thomas Schlichter

P.S.: The high idle temperature only shows if the  IOAPIC is used.
P.P.S: I already sent this mail last saturday, but as it seems to have never 
reached LKML I send it again. I'm sorry if you got it twice!