Bug 283364

Summary:	[PATCH] java/openjdk*: Update pkg-message information about fdescfs and procfs
Product:	Ports & Packages	Reporter:	Xavier Beaudouin <kiwi>
Component:	Individual Port(s)	Assignee:	freebsd-java (Nobody) <java>
Status:	New ---
Severity:	Affects Some People	CC:	0mp, haraldei-freebsdbugz
Priority:	---
Version:	Latest
Hardware:	Any
OS:	Any
See Also:	https://reviews.freebsd.org/D48111

Description Xavier Beaudouin freebsd_committer

2024-12-16 14:50:43 UTC

OpenJDK installation inform that fdescfs(5) and procfs(5) should be
mounted when using OpenJDK.
After doing some test and some traces, it seems that this should be
no so usefull, some applications will require it, but most of java
applications doesn't seems to suffer to work or performance when
such pseudo FS is not mounted.

So this change request permit to let local administrator to decide if
it is really needed or not.

I have opened a Phabricator about this change or pkg-message, feel free
to participate.

Kind regards

Comment 1 Harald Eilertsen 2024-12-17 15:39:53 UTC

Did a quick scan through the OpenJDK sources, and found the following:

The most important use of /dev/fd is to be able to close any extra file descriptors that for some reason don't have the O_CLOEXEC flag set when a new process is forked.

/proc seems to be a bit more involved, and is used by the JVM for some memory management, and determining system characteristics of certain architectures. (PowerPC, s390, at least.) Not sure what impact it has to remove it, but the effects may not immediately be obvious.