<!DOCTYPE html><html><head><title></title><style type="text/css">p.MsoNormal,p.MsoNoSpacing{margin:0}</style></head><body><div>This looks fantastic, thank you so much! I can confirm that the proposed <br></div><div>design would solve my use-case.<br></div><div><br></div><div>I'd enjoy discussing the NMT event contract somewhere more specific<br></div><div>to the implementation, but I don't want to muddle this thread with <br></div><div>implementation details.<br><br>Carter Kozak<br><br></div><div><div>On Wed, Nov 30, 2022, at 03:37, Stefan Johansson wrote:<br></div></div><blockquote type="cite" id="qt" style=""><div>Hi Carter,<br></div><div><br></div><div>Your mail made me pick up an old item from my wishlist: to have native <br></div><div>memory tracking information available in JFR recordings. When we, in GC, <br></div><div>do improvements to decrease the native memory overhead of our <br></div><div>algorithms, NMT is a very good tool to track the progress. We have <br></div><div>scripts that sound very similar to what you describe and more than once <br></div><div>I've been thinking about adding this information into JFR. But it has <br></div><div>not been a priority and the greater value has been unclear.<br></div><div><br></div><div>Hearing that others might also benefit from such a change I took a <br></div><div>discussion with the JFR team on how to best proceed with this. I have <br></div><div>created a branch for this and will probably create a PR for it shortly, <br></div><div>but I thought I would drop it here first:<br></div><div><a href="https://github.com/kstefanj/jdk/tree/8157023-jfr-events-for-nmt">https://github.com/kstefanj/jdk/tree/8157023-jfr-events-for-nmt</a><br></div><div><br></div><div>The change adds two new JFR events: one for the total usage and one for <br></div><div>the usage of each memory type. These are sent only if Native Memory <br></div><div>Tracking is turned on, and they are enabled in the default JFR profile <br></div><div>with an interval of 1s. This might change during reviewing but it was a <br></div><div>good starting point.<br></div><div><br></div><div>With this you will be able to use JFR streaming to access the events <br></div><div>from within your running process. I hope this will help your use cases <br></div><div>and please let us know if you have any comments or suggestions.<br></div><div><br></div><div>Thanks,<br></div><div>Stefan<br></div></blockquote><div><br></div></body></html>