Date: Thu, 4 Oct 2012 03:40:14 +1000 (EST) From: Ian Smith <smithi@nimnet.asn.au> To: Andriy Gapon <avg@freebsd.org> Cc: Sean Bruno <seanbru@yahoo-inc.com>, "freebsd-acpi@freebsd.org" <freebsd-acpi@freebsd.org> Subject: Re: notify userland about C-state changes Message-ID: <20121004031100.P43208@sola.nimnet.asn.au> In-Reply-To: <506C66A6.4070003@FreeBSD.org> References: <504EDBEB.6010104@FreeBSD.org> <1349198313.4246.3.camel@powernoodle.corp.yahoo.com> <506C38CE.4090400@FreeBSD.org> <1349281266.13749.0.camel@powernoodle.corp.yahoo.com> <506C66A6.4070003@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, 3 Oct 2012, Andriy Gapon wrote: > on 03/10/2012 19:21 Sean Bruno said the following: > > On Wed, 2012-10-03 at 06:08 -0700, Andriy Gapon wrote: > >>> > >>> So quick question, does this happen a lot on a system with a > >> sporadic > >>> workload? Does this introduce overhead to the system to service the > >>> notification requests? > >> > >> I am not sure who can answer this question. It is up to ACPI platform > >> to decide > >> when it changes _available C-states_. OS doesn't have control over > >> that. If you give us the notification :) we could instrument behaviour on different systems, and check for correlation with your [?] .. > >> > > Hrm ... what changes to the machine would make this happen while the > > machine is running? things like the switching from battery to line > > power? > > Yes. Or something else [?] of similar nature/effect. Docking/undocking a laptop maybe? LAN/Wireless busy/not (re C3 anyway). As you say, up to ACPI code by vendor, modulo ASL tweaks. > >> P.S. I hope you haven't confused this notification for a notification > >> about > >> _current_ C-state changing. > > > > I did have it confused. Thanks for putting this note in. > > OK :-) Me too .. my first reaction was ooo, that could get really busy :) So are you talking about a devd notification to trigger activity like the AC/battery script, or a sysctl that scripts could poll, or? cheers, Ian
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20121004031100.P43208>