Fast Sync Data Mover

[g. desbiens]

Hello,

Any reason why the "Fast Sync Data Mover" feature is disabled in Hercules? It's a freebie! It is just a flag that instructs certain ESA/390 mode applications to use the Move Page facility (which is implemented in Hercules) instead of the Async Data Mover facility if it is not installed.

Since the Async Data Mover facility is not implemented in Hercules (and probably never will), why disable a pseudo-feature that -does- exist? All that needs to happen is to uncomment this line in service.c:

//                      | SCCB_CFG0_FAST_SYNCHRONOUS_DATA_MOVER

Thank you,
Guy.

[g. desbiens]

Ok, I though I'd do some homework... I was able to test using a VMWare Ubuntu appliance; the host platform is Win-64. Starting with the Hercules SVN-5406 level source, I made these changes:

In service.c, replaced:

//                      | SCCB_CFG0_FAST_SYNCHRONOUS_DATA_MOVER

with:

#if defined(FEATURE_FAST_SYNC_DATA_MOVER)
                        | SCCB_CFG0_FAST_SYNCHRONOUS_DATA_MOVER
#endif /*defined(FEATURE_FAST_SYNC_DATA_MOVER)*/

In featchk.h, added:

#if defined(FEATURE_FAST_SYNC_DATA_MOVER) \
 && !defined(FEATURE_MOVE_PAGE_FACILITY_2)
 #error Fast sync data mover facility requires Move page facility
#endif

In featall.h, added:

#undef FEATURE_FAST_SYNC_DATA_MOVER

In feat390.h, added:

#define FEATURE_FAST_SYNC_DATA_MOVER

I built Hercules and verified that the fast sync data mover feature is working as designed. The facility (again it's just a flag) is described in the "System overview" documents for the G5/G6 processors all the way up to Z9 BC/EC. Ref. docs:

GA22-1030-03a, GA22-7158-06a, SA22-6833-06a and SA22-1083-04a.

This is narrow in scope but can be useful to take advantage of xstor in ESA/390 mode under some circumstances. Any objection to this feature being enabled in the main code?

Thanks,
Guy.

--- In hercules-390@..., "g. desbiens" <oc66@...> wrote:

>
> Hello,
>
> Any reason why the "Fast Sync Data Mover" feature is disabled in Hercules? It's a freebie! It is just a flag that instructs certain ESA/390 mode applications to use the Move Page facility (which is implemented in Hercules) instead of the Async Data Mover facility if it is not installed.
>
> Since the Async Data Mover facility is not implemented in Hercules (and probably never will), why disable a pseudo-feature that -does- exist? All that needs to happen is to uncomment this line in service.c:
>
> //                      | SCCB_CFG0_FAST_SYNCHRONOUS_DATA_MOVER
>
> Thank you,
> Guy.
>