RFR: 8356233: NMT: tty->print_cr should not be used in VirtualMemoryTracker::add_reserved_region() [v2]

[David Holmes]

On Tue, 20 May 2025 16:05:38 GMT, Gerard Ziemski <gziemski at openjdk.org> wrote:

>> To help with debugging NMT we added more info when an assert gets triggered, but we used `tty`, which is involved with locks and unfortunately it triggered:
>> 
>> 
>> # Internal Error (.../open/src/hotspot/share/runtime/mutex.cpp:457), pid=1088443, tid=1088520
>> # assert(false) failed: Attempting to acquire lock tty_lock/tty out of order with lock NmtVirtualMemory_lock/service-4 -- possible deadlock
>> 
>> 
>> We avoid this, by printing using `UL` instead of using `tty` directly.
>
> Gerard Ziemski has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Johan's feedback

LGTM.

Thanks

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Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/25308#pullrequestreview-2855726330