On Mon, Feb 01, 2010 at 03:10:38PM +0100, Pavel Machek wrote: > On Tue 2010-01-26 02:47:40, Jeff Garrett wrote: > > Hi, > > > > I was trying to chase down a theory that my desktop machine (a core i7) > > is running warm (the fan sounds like it's at full speed all the time, > > and I think it's not always acted this way -- hence the theory). > > > > powertop is never showing it spending any time in C3... > > > > I compiled a kernel without USB/sound/radeon, and ran without X. I was > > able to get the wakeups/sec down below 20, but no time is spent in C3. > > > This may be a complete red herring, but I added some printk logic to > > acpi_idle_bm_check(), and it is getting called often, but bm_status is > > always 1. [I infer from this that the idle logic is trying to go into > > C3, but this check is stopping it... Unless I misread something.] > > > > Is this expected behavior or is this a legitimate problem? > > > > How might I investigate this further? > > DMA keeps system awake? Possibly USB? X is not running. USB is not enabled at all (CONFIG_USB_SUPPORT is not set), and likewise for sound & drm. What could be doing the DMA? :) If there is DMA, it could be disk or network related. However, I find it hard to believe that this activity is so constant on a nearly idle system... Of course, I haven't thought of a way to test this yet. Attaching my config & dmesg of my latest try. Thanks, -Jeff