On Thu, 24 Aug 2023 23:31:56 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:

> On some macosx-aarch64 systems, not all mapped pages are dumped to the core 
> file. This first turned up with 
> [JDK-8293563](https://bugs.openjdk.org/browse/JDK-8293563) where large parts 
> of the ZGC heap would not be in the core file, leading to various SA address 
> errors. For JDK-8293563 the issue was addressed by having the core file test 
> always use `-XX:+AlwaysPreTouch` on macosx-aarch64. This seemed to force the 
> ZGC pages to always end up in the core file.
> 
> A similar issue has been noticed with mapped in pages of the CDS archive. We 
> are seeing cases where SA references to addresses that are clearly in the CDS 
> archive (based on info in the hs_err file) are failing to be read from the 
> core file by SA. This problem has turned up a number of times during CI 
> testing, but I have yet to be able to reproduce it myself. This PR is an 
> attempt to address this testing issue by having the CDS archive also pretouch 
> all mapped in pages when `-XX:+AlwaysPreTouch` is used.
> 
> Tested with tier1 and tier3 and also ran the test about 5,000 times with and 
> without the fix. It never reproduced for either. Hopefully the problem is 
> gone with this fix, but it may take a few months of CI testing before we can 
> be confident it is fixed.

This pull request has now been integrated.

Changeset: d0cc0439
Author:    Chris Plummer <cjplum...@openjdk.org>
URL:       
https://git.openjdk.org/jdk/commit/d0cc0439c07ad0cca611e1999eda37f20c5a99d0
Stats:     22 lines in 1 file changed: 14 ins; 0 del; 8 mod

8314550: [macosx-aarch64] serviceability/sa/TestJmapCore.java fails with 
"sun.jvm.hotspot.debugger.UnmappedAddressException: 801000800"

Reviewed-by: dholmes, iklam, stuefe

-------------

PR: https://git.openjdk.org/jdk/pull/15423

Reply via email to