On Mon, 26 Oct 2020 06:10:52 GMT, Nick Gasson <ngas...@openjdk.org> wrote:
>>> >>> 1. Like Alexey, I would really wish for an print-at-exit switch. The >>> common naming seems to be xxxAtExit (so not, OnExit). "PrintXxx" seems to >>> be printing stuff out to tty, "DumpXxxx" for writing separate files (e.g. >>> CDS map). So I would name it DumpPerfMapAtExit. >>> >> >> OK, makes sense. >> >>> 2. Dumping to /tmp is unexpected for me, I would prefer if the default >>> were dumping to the current directory. That seems to be the default for >>> other files too (cds map, hs-err file etc). >>> >>> 3. Not necessary but nice would be a an option to specify location of >>> the dump file. >>> >> >> The `/tmp/perf-<pid>.map` is hardcoded into perf though ([see >> here](https://github.com/torvalds/linux/blob/master/tools/perf/util/map.c#L155)), >> so I don't think it's useful for the user to be able to change the location. > >> >> I think we should use this option carefully because nmethod might be >> unloaded. So we should use this with `-XX:-UseCodeCacheFlushing`. >> > > Thanks for the information. `-XX:+DumpPerfMapAtExit` will turn on > `UseCodeCacheFlushing` if it's set to default. I don't see any reason for this to be a product flag, rather than diagnostic. ------------- PR: https://git.openjdk.java.net/jdk/pull/760
