Integrated: JDK-8296931: NMT tests slowed down considerably by JDK-8242181

[Thomas Stuefe]

On Mon, 14 Nov 2022 12:43:41 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> We noticed that NMT tests on our slower PPC machines started failing.
> 
> The reason is that NMT detail reports have become 2-5x slower. This is caused by us now parsing the dwarf debug information to extract source information for each PC in each call stack. That is nice but costly.
> 
> The slowdown is not limited to PPC, it affects all Elf platforms. On my Linux x64 box, runtime/NMT/VirtualAllocCommitMerge.java increased from 20 to 90 seconds.
> 
> ---
> 
> This patch simply removes source info from NMT call stacks. They are not that important for pinpointing leaks and such. I considered more involved solutions, like making them optional via an argument to the NMT report command, but decided against it. The added benefit would be small, not worth much complexity.
> 
> With this patch, on my box with -conc 4 all NMT together are about 2.5 x faster (2m56 -> 1m09).

This pull request has now been integrated.

Changeset: 5e08b3f4
Author:    Thomas Stuefe <stuefe at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/5e08b3f40e04254276fc2d37c523cb06b121861a
Stats:     5 lines in 1 file changed: 1 ins; 1 del; 3 mod

8296931: NMT tests slowed down considerably by JDK-8242181

Reviewed-by: chagedorn, mbaesken

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PR: https://git.openjdk.org/jdk/pull/11135