Date: Sat, 28 Jan 2006 22:17:47 -0800 From: Nate Lawson <nate@root.org> To: Kris Kennaway <kris@obsecurity.org> Cc: cvs-src@FreeBSD.org, Nate Lawson <njl@FreeBSD.org>, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/etc/defaults rc.conf Message-ID: <43DC5E0B.40003@root.org> In-Reply-To: <20060129061300.GA47596@xor.obsecurity.org> References: <200601290551.k0T5pwEC028440@repoman.freebsd.org> <20060129060654.GA47495@xor.obsecurity.org> <20060129061300.GA47596@xor.obsecurity.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Kris Kennaway wrote: > On Sun, Jan 29, 2006 at 01:06:54AM -0500, Kris Kennaway wrote: > >>On Sun, Jan 29, 2006 at 05:51:58AM +0000, Nate Lawson wrote: >> >>>njl 2006-01-29 05:51:58 UTC >>> >>> FreeBSD src repository >>> >>> Modified files: >>> etc/defaults rc.conf >>> Log: >>> Enable the lowest Cx state by default. This will save power and we have >>> had enough testing of acpi_cpu to know this is stable now. >> >>On my desktop system (running RELENG_6 though), setting >>hw.acpi.cpu.cx_lowest=C0 causes atrocious performance. Is it broken >>in 6.x? > > C2, sorry. Ah, C0 should be disallowed already I thought (try it). As for C2, I MFCd a patch to acpi_cpu.c in November that should prevent this (1.57.2.1). Do you get a printf on console? Commit msg: If we're trying to use C2/3 and reads from the register are returning immediately, back off to the next higher Cx sleep state. Some machines with a Via chipset report a valid C3 but a register read doesn't actually halt the CPU. This would cause the machine to appear unresponsive as it repeatedly called cpu_idle() which immediately returned. Causing interrupts (i.e. by pressing the power button) would cause the system to make forward progress, showing that it wasn't actually hung. Also, enable interrupts a little earlier. We don't need them disabled to calculate the delta time for the read. -- Nate
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?43DC5E0B.40003>