_CSD is the way BIOS coomunicates the C-state dependencies across cores in the system. The way _CSD is defined, OS communicates with BIOS about its capability through _PDC or _OSC and BIOS can then return methods like _PSD and _CSD. _CSD is not supported in Linux right now. Having said that, _CSD is not really interesting on Intel CPUs at this time as C-states are hardware coordinated. That means, OS can make each CPU enter C-state independently (assuming each core is independent) and hardware will do the required coordination underneath.
Thanks, Venki >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] On Behalf Of Martin Wilck >Sent: Tuesday, February 26, 2008 5:42 AM >To: [email protected] >Subject: [Discuss] _CSD support > >Hi, > >I have looked for _CSD support in the Linux ACPI code, but found >nothing. Isn't that necessary for package C-state support on multicore >systems? > >Martin > >-- >Martin Wilck >PRIMERGY System Software Engineer >FSC IP ESP DE6 > >Fujitsu Siemens Computers GmbH >Heinz-Nixdorf-Ring 1 >33106 Paderborn >Germany > >Tel: ++49 5251 8 15113 >Fax: ++49 5251 8 20209 >Email: mailto:[EMAIL PROTECTED] >Internet: http://www.fujitsu-siemens.com >Company Details: http://www.fujitsu-siemens.com/imprint.html > >_______________________________________________ >Discuss mailing list >[email protected] >http://mail.lesswatts.org/mailman/listinfo/discuss > _______________________________________________ Discuss mailing list [email protected] http://mail.lesswatts.org/mailman/listinfo/discuss
