RFR: 8354938: ZGC: Disable UseNUMA when ZFakeNUMA is used

Thu Apr 17 12:05:44 UTC 2025

ZFakeNUMA is used to fake a number of NUMA nodes within ZGC. The intention was to make ZFakeNUMA mutually exclusive with UseNUMA, but the current code allows the user to enable UseNUMA and set ZFakeNUMA, which will trigger to the "mutual exclusion" assert in ZNUMA::initialize.

Verified on NUMA machine with -XX:+UseNUMA -XX:ZFakeNUMA=<count>. Will run this through our lower tiers.

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Commit messages:
 - 8354938: ZGC: Disable UseNUMA when ZFakeNUMA is used

Changes: https://git.openjdk.org/jdk/pull/24721/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24721&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354938
  Stats: 13 lines in 1 file changed: 10 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/24721.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24721/head:pull/24721

PR: https://git.openjdk.org/jdk/pull/24721