Integrated: JDK-8319314: NMT detail report slow or hangs for large number of mappings

[Thomas Stuefe]

On Thu, 2 Nov 2023 16:42:58 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> If a lot of mappings have been registered with NMT, NMT detail report may get so slow as to hang seemingly. 
> 
> 100 k mappings will take > 1 minute
> 1 million mappings never returns (I canceled the test after 90 minutes)
> 
> We burn all the time doing a sorted insert into the target array of the MemBaseline object. That sorted insert is pointless since the source array is already sorted by region base address.
> 
> Omitting the pointless sort drops the runtime for 1 million mappings from > 90 minutes to 48 seconds.
> 
> Tests: Tested locally. GHAs (Windows error unrelated).

This pull request has now been integrated.

Changeset: 9938b3f6
Author:    Thomas Stuefe <stuefe at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/9938b3f62babfc35ee682bd979a6bf08ac7cd348
Stats:     18 lines in 1 file changed: 8 ins; 5 del; 5 mod

8319314: NMT detail report slow or hangs for large number of mappings

Reviewed-by: jsjolen, gziemski

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PR: https://git.openjdk.org/jdk/pull/16480