On Sun, 10 Jun 2007 12:02:00 -0600, Robert Hancock wrote: > Mikael Pettersson wrote: > > On Fri, 08 Jun 2007 10:14:03 +0200, Gerard H. Pille wrote: > >> [1.] One line summary of the problem: > >> Since I switched from 2.6.20 to 2.6.21 on my Athlon AMD64 laptop, the > >> system > >> time is slow - about 1' on 15'. > > > > According to your system description it seems that you have a > > Targa Visionary laptop with a VIA chipset and a Mobile Athlon64. > > If so, then you probably have the same problem I reported some time > > ago: see <http://marc.info/?l=linux-kernel&m=117681226421346&w=2> > > and the followup messages. The conclusion was that the chipset's > > ACPI PM timer slows down when the CPU is in C2. > > > > The workaround is to boot with processor.max_cstate=1. > > Which, if true, is extremely bizarre, as the whole point and reason for > existence of the ACPI PM timer is that it NOT do this, and remain at the > same rate regardless of CPU power management changes..
If you read the thread you'll find another bizarre fact: my laptop only saw acpi_pm lose time when running a 64-bit kernel. With the 32-bit kernel acpi_pm worked fine in C2. The C1 workaround is what the ACPI folks came up with. I was reluctant to use it at first, but haven't really noticed any negative effects. /Mikael - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
