RFR: 8273635: Attempting to acquire lock StackWatermark_lock/9 out of order with lock tty_lock/3

Coleen Phillimore coleenp at openjdk.java.net
Mon Sep 13 22:24:51 UTC 2021


On Mon, 13 Sep 2021 20:04:56 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> This change reverts the rank ordering of ttyLock and StackWatermark_lock because the latter is held through a very large region and printing all of this to a buffer with xmlstream is non-trivial.
> With this change, if tty->print_cr() is done while holding the stackwatermark lock or lower (which is service ranking, etc), a lock inversion will happen with ttyLock.  This doesn't happen now because all the code in GC and much of the rest of the runtime use UL and not tty->print().
> Tested with tier1-6.

Thanks for the review, David!

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PR: https://git.openjdk.java.net/jdk/pull/5499


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