I am not sure how much more efficient using a two MODESET SVCs to flip in and out of Key0/Sup would be compared to a single PC-ss.
I would also advise to not use key0 for any of your application memory unless absolutely necessary. Have you considered a PPT entry for your jobstep program so that your code could get assigned to something like key2 or key4 ? Depending on what your application does, you might be able to achieve your design goals without having to ever switch keys out of key2/4. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Charles Mills Sent: Wednesday, December 14, 2016 4:12 PM To: [email protected] Subject: Re: Question on SPKA and Control Register 3 Well, yes, the why is to access shared 64-bit common. It's worked well for years. A PC service to move some data and increment a pointer (millions of times per hour) seemed like overkill. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Rob Scott Sent: Wednesday, December 14, 2016 7:14 AM To: [email protected] Subject: Re: Question on SPKA and Control Register 3 Charles I am struggling to understand why you would want to run key0 and problem state anyway - it seems like a very strange brew and a bit of an oxymoron. Another question - why do you need Key0 in the first place? Is it just to access non-user key CSA ? If you have code that is running 99.9% of the time in user key and problem state and it requires some sort of authorized/supervisor service, then I would suggest implementing some sort of request to a service provider (maybe via PC-ss) to perform an encapsulated service on the caller's behalf. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ================================ Rocket Software, Inc. and subsidiaries ■ 77 Fourth Avenue, Waltham MA 02451 ■ +1 877.328.2932 ■ +1 781.577.4321 Unsubscribe from Marketing Messages/Manage Your Subscription Preferences - http://www.rocketsoftware.com/manage-your-email-preferences Privacy Policy - http://www.rocketsoftware.com/company/legal/privacy-policy ================================ This communication and any attachments may contain confidential information of Rocket Software, Inc. All unauthorized use, disclosure or distribution is prohibited. If you are not the intended recipient, please notify Rocket Software immediately and destroy all copies of this communication. Thank you. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
