Trashing the I Cache is still very much a concern. Cheers, Martin
Martin Packer, Mainframe Performance Consultant, zChampion Worldwide Banking Center of Excellence, IBM +44-7802-245-584 email: [email protected] Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker From: John McKown <[email protected]> To: [email protected], Date: 11/04/2012 10:20 Subject: Re: CALL macro "enhancement" thought Sent by: IBM Mainframe Assembler List <[email protected]> Good question. I remember back on the z890 there was a separate cache for data and instructions. I think that is still true. I do remember that writing to a storage location which was in the I-cache caused a cache flush of some sort. And that could really hurt performance. I don't know how many separate "areas" are in the cache, but I would guess that loading the D-cache from a non-cached area would "replace" the contents of at least one of the D-cache buffers. I'm not a hardware person. I wonder if the performance would improve enough to be cost effective if data could be fetched from the I-cache. On Tue, 2012-04-10 at 18:52 -0400, Kirk Talman wrote: > Does the data intermingled with the instructions cause a performance > problem? > -- John McKown Maranatha! <>< Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
