Skip to Main Content
IBM Z Software


This portal is to open public enhancement requests against IBM Z Software products. To view all of your ideas submitted to IBM, create and manage groups of Ideas, or create an idea explicitly set to be either visible by all (public) or visible only to you and IBM (private), use the IBM Unified Ideas Portal (https://ideas.ibm.com).


Shape the future of IBM!

We invite you to shape the future of IBM, including product roadmaps, by submitting ideas that matter to you the most. Here's how it works:

Search existing ideas

Start by searching and reviewing ideas and requests to enhance a product or service. Take a look at ideas others have posted, and add a comment, vote, or subscribe to updates on them if they matter to you. If you can't find what you are looking for,

Post your ideas
  1. Post an idea.

  2. Get feedback from the IBM team and other customers to refine your idea.

  3. Follow the idea through the IBM Ideas process.


Specific links you will want to bookmark for future use

Welcome to the IBM Ideas Portal (https://www.ibm.com/ideas) - Use this site to find out additional information and details about the IBM Ideas process and statuses.

IBM Unified Ideas Portal (https://ideas.ibm.com) - Use this site to view all of your ideas, create new ideas for any IBM product, or search for ideas across all of IBM.

ideasibm@us.ibm.com - Use this email to suggest enhancements to the Ideas process or request help from IBM for submitting your Ideas.

Status Delivered
Categories z/TPF
Created by Guest
Created on Jun 26, 2024

Optimize tagged heap lookup service routine.

Currently tpf_eheap_tag() and tpf_eheap_locate() are convenient APIs to retrieve heap buffer addresses across an ECB's lifetime. The tpf_eheap_locate() service routine in the CP executes a sequential search through all heap buffers until the provided tag is found. We have seen a trend in our applications code where tagged heap is being more widely adopted despite recommendations to avoid the mechanism unless absolutely necessary. This trend is becoming more of a concern as we have seen noticeable CPU increases on our PROD systems that can be attributed to increased hits in CCSTOR (tagged heap lookup routines specifically). Assuming this trend continues and efforts to move away from the mechanism are not fruitful, ideally the sequential search should be optimized to mitigate the overhead associated with the search.

Idea priority Medium
  • Guest
    Reply
    |
    Dec 11, 2024
    This support is available with APAR PJ47265.