Integrated: 8323681: SA PointerFinder code should support G1

[Chris Plummer]

On Fri, 2 Feb 2024 23:24:20 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

> This PR adds G1 support to PointerFinder/PointerLocation. Previously we only had SerialGC support. Previously for G1 addresses SA would only report that the address is "In unknown section of Java heap" with no other details. Now it provides details for G1 addresses. Here are some examples for clhsdb `threadcontext` output. `threadcontext` dumps the contents of the thread's registers, some of which are often in the java heap. In the output below the first line is without verbose output and the 2nd is with:
> 
> 
> rbp: 0x00000000a0004080: In G1 heap region
> rbp: 0x00000000a0004080: In G1 heap Region: 0x00000000a0000000,0x00000000a0018a30,0x00000000a1000000:Old
> 
> 
> I also added an improvement to how SA deals with addresses in the TLAB. It used to only report that the address is in a TLAB and provide details about the TLAB in verbose mode. Now if verbose mode is used, the heap region information is included after the TLAB information. Here again is an example without and with verbose output:
> 
> 
> rsi: 0x0000000166000000: In TLAB for thread "main" sun.jvm.hotspot.runtime.JavaThread at 0x00007f11c8029250
> rsi: 0x0000000166000000: In TLAB for thread ("main" #1 prio=5 tid=0x00007f11c8029250 nid=1503 runnable [0x0000000000000000]
>    java.lang.Thread.State: RUNNABLE
>    JavaThread state: _thread_in_java
> )  [0x0000000166000000,0x00000001662d0c90,0x00000001667ffdc0,{0x0000000166800000})
> In G1 heap Region: 0x0000000166000000,0x0000000166800000,0x0000000167000000:Eden
> 
> 
> Note at the end it indicates the address is in the Eden space, which is probably always the case for G1 TLAB addresses. For SerialGC is shows something similar.
> 
> 
> rsi: 0x0000000088ff99e0: In TLAB for thread "main" sun.jvm.hotspot.runtime.JavaThread at 0x00007f0544029110
> rsi: 0x0000000088ff99e0: In TLAB for thread ("main" #1 prio=5 tid=0x00007f0544029110 nid=3098 runnable [0x0000000000000000]
>    java.lang.Thread.State: RUNNABLE
>    JavaThread state: _thread_in_java
> )  [0x0000000088ff99e0,0x000000008978c090,0x0000000089ae54b0,{0x0000000089ae56f0})
> In heap new generation:  eden [0x0000000080200000,0x0000000089ae56f0,0x00000000a2420000) space capacity = 572653568, 27.99656213789626 used
>   from [0x00000000a6860000,0x00000000a6860030,0x00000000aaca0000) space capacity = 71565312, 6.707160027472528E-5 used
>   to   [0x00000000a2420000,0x00000000a2420000,0x00000000a6860000) space capacity = 71565312, 0.0 used
> 
> 
> Testing all svc test in tier1, tier2, and tier5. Currently in progress.

This pull request has now been integrated.

Changeset: be7cc1c2
Author:    Chris Plummer <cjplummer at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/be7cc1c2b083ac7cbcec6b0fe77caff16f14bb60
Stats:     73 lines in 4 files changed: 57 ins; 6 del; 10 mod

8323681: SA PointerFinder code should support G1

Reviewed-by: tschatzl, kevinw

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PR: https://git.openjdk.org/jdk/pull/17691