Re: QPRCMLTTSK system value

[Vern Hamberg <vhamberg@xxxxxxxxxxx>]

Hi Pete

I can't find anything that connects the setting of this system value 
directly to Java performance. I googled for "qprcmlttsk java".

It is shipped as set to '1'. I understand that sometimes Linux won't run 
when this is set to '1' (from 2002 article by Larry Loen, I believe).

Since the default is to have it turned on, I'd say it's best to leave it 
that way. That is the gist of an InfoCenter article on when to use this 
feature. It appears that things should not go more slowly when this is 
on, but you won't gain double the speed from the 2 paths in a CPU in 
earlier processor since NorthStar. POWER7 seems now to support 4 
hardware threads on a core.

This is only a guess based on my reading, but I'd say it probably can't 
hurt to leave it on. Unless you have Linux in a partition.

Vern

Pete Hall wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> I'm considering setting QPRCMLTTSK to '1' on an 825 (V540) for improved
> Java performance. Does anyone have any horror stories about it? Heavy
> batch processing occurs on this system each night, and there's still a
> significant single threaded interactive/batch mix during the day. Since
> this setting is inherited from the controlling partition on 7xx and 8xx
> machines, I can't test it on the dev LPAR first.
>
> - --
> Pete Hall
> pete@xxxxxxxxxxxxxx
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.9 (GNU/Linux)
>
> iEYEARECAAYFAkuJsj0ACgkQXczQcKdXKg4FNACfVKAv1fIviepIxjHkTD7UAQKz
> 6lgAoKbVQkkLJhu5ysZoN1tT3e4p4YQl
> =B7uy
> -----END PGP SIGNATURE-----
>