AW: Re: RSM Freemained Frames - When do they apply?

> RSM will free frames if available frames are in short supply. > If you obtain a smaller amount, get it backed, and then release it, you > may be more likely to observe the frames being retained. I've changed the program to allocate 8KiB areas instead of 10MiB, and RSM decides to keep the

Re: RSM Freemained Frames - When do they apply?

ssion List" <IBM-MAIN@LISTSERV.UA.EDU> wrote on 12/15/2017 07:31:53 AM: > From: "Christopher Y. Blaicher" <cblaic...@syncsort.com> > To: IBM-MAIN@LISTSERV.UA.EDU > Date: 12/15/2017 07:12 PM > Subject: Re: RSM Freemained Frames - When do they apply? > Sen

Re: RSM Freemained Frames - When do they apply?

To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: RSM Freemained Frames - When do they apply? Interesting detail: why does this work on z13 only and not on z14? Grtn, Kees. > -Original Message- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] > On Behalf Of J

Re: RSM Freemained Frames - When do they apply?

; Subject: Re: RSM Freemained Frames - When do they apply? > > RSM will free frames if available frames are in short supply. > If you obtain a smaller amount, get it backed, and then release it, you > may > be more likely to observe the frames being retained. > > Jim Mulder z/OS Di

AW: Re: RSM Freemained Frames - When do they apply?

>If you obtain a smaller amount, get it backed, and then release it, you may be more likely to observe the frames being retained. Thanks. I (wrongly, it seems) assumed it is more likely to happen with large areas. -- Peter Hunkeler

AW: Re: AW: Re: RSM Freemained Frames - When do they apply?

>It avoids the issuance of IPTE (an expensive instruction when many CPs are >present) for each frame... I know. Had I not been too lazy to open the PoOp, and read what exactly the IPTE does, I had written "it avoids updating the TLB..." instead of "it probably avoids...". I promis to do

Re: RSM Freemained Frames - When do they apply?

RSM will free frames if available frames are in short supply. If you obtain a smaller amount, get it backed, and then release it, you may be more likely to observe the frames being retained. Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY > Running z/OS V2.2

Re: AW: Re: RSM Freemained Frames - When do they apply?

On 12/14/2017 1:13 PM, Peter Hunkeler wrote: The APAR decribes that marking frames as freemained frames avoids signaling all processors, which does not scale well with the large number of processors in z13 and newer machines. It probably avoids updating the TLBs. It avoids the issuance of

AW: Re: RSM Freemained Frames - When do they apply?

>My guess is that the TLB has not been updated yet. That save performance as the unallocation can wait until all CPs running in the address space have had normal interrupts to process the changes. The unallocation can wait until RSM sees a need to put them onto the available frames queue. It

AW: Re: RSM Freemained Frames - When do they apply?

>This not much different from the old situation, where you getmain a page, >freemain half of it, so the frame still remains valid and is fully accessible. Yes, it is much different! In the case you describe, you will find the page is allocated in the VSMDATA report. With freemained frames,

Re: RSM Freemained Frames - When do they apply?

On Thu, 14 Dec 2017 14:04:02 + "Vernooij, Kees (ITOPT1) - KLM" wrote: :>What does this exactly mean: "freemained frames"? Is it just a counter or do they refer to specific frames, that are kept at hand in the address space for faster assignment of new frame requests?

Re: AW: Re: RSM Freemained Frames - When do they apply?

On 12/14/2017 6:47 AM, Peter Hunkeler wrote: See OA46291. The APAR is for z/OS V2.1 and V1.13, it is in the base for z/OS V2.2. Also this great write-up put together by Elipda Tzortatos http://publibz.boulder.ibm.com/zoslib/pdf/OA46291.pdf With this new function, RSM (SRM?) may decide

Re: RSM Freemained Frames - When do they apply?

> -Original Message- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of Peter Hunkeler > Sent: 14 December, 2017 15:47 > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: AW: Re: RSM Freemained Frames - When do they apply? > > > &

Re: RSM Freemained Frames - When do they apply?

On Thu, Dec 14, 2017 at 8:47 AM, Peter Hunkeler wrote: > > >What does this exactly mean: "freemained frames"? Is it just a counter or > do they refer to specific frames, that are kept at hand in the address > space for faster assignment of new frame requests? > > > >I am not

AW: Re: RSM Freemained Frames - When do they apply?

>What does this exactly mean: "freemained frames"? Is it just a counter or do >they refer to specific frames, that are kept at hand in the address space for >faster assignment of new frame requests? > >I am not surprised that those frames, if they are "available" at all, are not >accessible

Re: RSM Freemained Frames - When do they apply?

> -Original Message- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > Behalf Of Gord Tomlin > Sent: 14 December, 2017 14:45 > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: RSM Freemained Frames - When do they apply? > > On 2017-12-14 07:

Re: RSM Freemained Frames - When do they apply?

On 2017-12-14 07:04, Peter Hunkeler wrote: Running z/OS V2.2 on a z13. "D DIAG" shows FREEMAINEDFRAMES(YES) I'm not trying to solve any specific problem. I'm just curious. I'd like to see the behaviour in different situations when real storage (frames) has been kept as part of RSMs new

RSM Freemained Frames - When do they apply?

Running z/OS V2.2 on a z13. "D DIAG" shows FREEMAINEDFRAMES(YES) I'm not trying to solve any specific problem. I'm just curious. I'd like to see the behaviour in different situations when real storage (frames) has been kept as part of RSMs new "freemained frames" feature after the virtual