Re: Explanation about the SVCASF bit ("SVC can be assisted") in the SVC table?
Thank you both for the historical perspective, and special thanks to Jim for the additional up-to-date clarification - it now makes much more sense. Best regards, Dori On Wed, Apr 4, 2018 at 8:44 PM, Jim Mulder wrote: > SVC Assist has not been used since MVS/ESA SP3.1.0 (30 years ago), > so the SVCASF bit has had no meaning for 30 years. It is on in the > SVC 13 and SVC 26 entries because of some obsolete code in > IEAVNPS5, which should have been deleted. However, this causes > no harm, since the bit is not used for anything. > > Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. > Poughkeepsie NY > > IBM Mainframe Discussion List wrote on > 04/04/2018 11:33:07 AM: > > > From: Rob Scott > > To: IBM-MAIN@LISTSERV.UA.EDU > > Date: 04/04/2018 12:36 PM > > Subject: Re: Explanation about the SVCASF bit ("SVC can be > > assisted") in the SVC table? > > Sent by: IBM Mainframe Discussion List > > > > "SVC Assist" is a facility that performed some common housekeeping > > operations on behalf of the SVC - for example, copying the information > > stored at the last SVC interruption into the current request block, > > saving general registers, and loading the general registers with > > appropriate values. > > > > It was implemented by opcode x'E503'. > > > > -Original Message- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU > > ] On Behalf Of Dori Polotsky > > Sent: Wednesday, April 4, 2018 10:18 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Explanation about the SVCASF bit ("SVC can be assisted") in > > the SVC table? > > > > Hello, > > > > Does anyone know the meaning of the SVCASF bit (x'01') of the SVCTP > > byte of the SVC table? > > > > If I am not mistaken, on our system (z/OS 2.2 ADCD) following the > > IPL this bit is off for all SVC's except SVC 13 (ABEND, IEAVTRT2) > > and SVC 26 (LOCATE / CATALOG, IGG026DU). Also, I did not see an > > option to select the value for this bit with SVCUPDTE. > > > > Any insights would be appreciated. > > > > Thank you very much, > > Dori > > > > -- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > -- [image: Model9] Dori Polotsky R&D m: +972-54-4584663 e: dori.polot...@model9.io w: www.model9.io -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
Re: Explanation about the SVCASF bit ("SVC can be assisted") in the SVC table?
SVC Assist has not been used since MVS/ESA SP3.1.0 (30 years ago), so the SVCASF bit has had no meaning for 30 years. It is on in the SVC 13 and SVC 26 entries because of some obsolete code in IEAVNPS5, which should have been deleted. However, this causes no harm, since the bit is not used for anything. Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY IBM Mainframe Discussion List wrote on 04/04/2018 11:33:07 AM: > From: Rob Scott > To: IBM-MAIN@LISTSERV.UA.EDU > Date: 04/04/2018 12:36 PM > Subject: Re: Explanation about the SVCASF bit ("SVC can be > assisted") in the SVC table? > Sent by: IBM Mainframe Discussion List > > "SVC Assist" is a facility that performed some common housekeeping > operations on behalf of the SVC - for example, copying the information > stored at the last SVC interruption into the current request block, > saving general registers, and loading the general registers with > appropriate values. > > It was implemented by opcode x'E503'. > > -Original Message- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU > ] On Behalf Of Dori Polotsky > Sent: Wednesday, April 4, 2018 10:18 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Explanation about the SVCASF bit ("SVC can be assisted") in > the SVC table? > > Hello, > > Does anyone know the meaning of the SVCASF bit (x'01') of the SVCTP > byte of the SVC table? > > If I am not mistaken, on our system (z/OS 2.2 ADCD) following the > IPL this bit is off for all SVC's except SVC 13 (ABEND, IEAVTRT2) > and SVC 26 (LOCATE / CATALOG, IGG026DU). Also, I did not see an > option to select the value for this bit with SVCUPDTE. > > Any insights would be appreciated. > > Thank you very much, > Dori -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
Re: Explanation about the SVCASF bit ("SVC can be assisted") in the SVC table?
"SVC Assist" is a facility that performed some common housekeeping operations on behalf of the SVC - for example, copying the information stored at the last SVC interruption into the current request block, saving general registers, and loading the general registers with appropriate values. It was implemented by opcode x'E503'. -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Dori Polotsky Sent: Wednesday, April 4, 2018 10:18 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Explanation about the SVCASF bit ("SVC can be assisted") in the SVC table? Hello, Does anyone know the meaning of the SVCASF bit (x'01') of the SVCTP byte of the SVC table? If I am not mistaken, on our system (z/OS 2.2 ADCD) following the IPL this bit is off for all SVC's except SVC 13 (ABEND, IEAVTRT2) and SVC 26 (LOCATE / CATALOG, IGG026DU). Also, I did not see an option to select the value for this bit with SVCUPDTE. Any insights would be appreciated. Thank you very much, Dori -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN Rocket Software, Inc. and subsidiaries ■ 77 Fourth Avenue, Waltham MA 02451 ■ Main Office Toll Free Number: +1 855.577.4323 Contact Customer Support: https://my.rocketsoftware.com/RocketCommunity/RCEmailSupport 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 lists...@listserv.ua.edu with the message: INFO IBM-MAIN
Explanation about the SVCASF bit ("SVC can be assisted") in the SVC table?
Hello, Does anyone know the meaning of the SVCASF bit (x'01') of the SVCTP byte of the SVC table? If I am not mistaken, on our system (z/OS 2.2 ADCD) following the IPL this bit is off for all SVC's except SVC 13 (ABEND, IEAVTRT2) and SVC 26 (LOCATE / CATALOG, IGG026DU). Also, I did not see an option to select the value for this bit with SVCUPDTE. Any insights would be appreciated. Thank you very much, Dori -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN