From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amit Kucheria Subject: Re: So, what's the status on the recent patches here? Date: Fri, 18 Aug 2006 14:48:39 +0300 Message-ID: <1155901719.3659.43.camel@localhost> References: <20060814200735.GC14099@kroah.com> <20060814224623.GH30814@redhat.com> <221e3d51950d20642b3655617527dc52@nomadgs.com> <20060814234801.GK30814@redhat.com> <20060815010020.GA14251@kroah.com> <1155638115.6736.135.camel@localhost> <20060815190439.GI7612@redhat.com> <1155806337.30834.17.camel@localhost> <20060817214031.GE6450@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20060817214031.GE6450@ucw.cz> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: ext Pavel Machek Cc: linux-pm@lists.osdl.org List-Id: linux-pm@vger.kernel.org On Thu, 2006-08-17 at 21:40 +0000, ext Pavel Machek wrote: = > > The userspace interface in Eungeny's patches is for other userspace > > programs (policy managers) to activate/deactivate valid operating points > > in the system dynamically and if necessary, introduce new ones into the > > system. It will also allow the operating points to be referenced by name > > instead of the tuple. > > = > > Then, we will be able to use names like 'video', 'mp3', 'fast', > > 'powersave', 'usb' to switch to the relevant operating point based on > > configuration of the policy manager. > = > This seems to be too specific to embedded machine. > = > If userspace wants to work with usb and play mp3s at the same time, > what does it do? Switch to 'fast'? The operating point for a use-case specifies the _minimum_ required for the use-case. You can always go up. The system designer is responsible for 'designing' operating points that take into account multiple use-cases. Designing here refers to mapping use-cases to HW operating points. Consider an example system with a main CPU and a DSP. To simplify discussion, lets assume 3 levels for CPU and DSP speeds and system voltage. Then, here is what an example operating-point to use-case mapping table could look like: # CPU speed DSP speed Voltage use-case ---------------------------------------------------------- 1. high high high fast, video 2. med high high = 3. med med med usb[1] 4. low med med mp3 5. low low low powersave [1] USB has voltage constraint (voltage >=3D med) Mapping =3D=3D=3D=3D=3D=3D=3D Performance related: fast, video, mp3 Power related: powersave Miscellaneous: usb - Now if we are playing mp3, we switch to OP 4. - Add usb and we switch to OP 3. - Now our performance monitor (e.g load avg) indicates that we need more CPU processing. So we switch to OP 2. Regards, Amit -- = Amit Kucheria Nokia