On Fri, May 15, 2020 at 10:23:17AM -0500, Nate Karstens wrote:

This functionality was approved by the Austin Common Standards
Revision Group for inclusion in the next revision of the POSIX
standard (see issue 1318 in the Austin Group Defect Tracker).

It penalizes every call of fork() in the system (as well as adds
an extra dirtied cacheline on each socket()/open()/etc.), adds
memory footprint and complicates the API.  All of that - to deal
with rather uncommon problem that already has a portable solution.

As for the Austin Group, the only authority it has ever had derives
from consensus between existing Unices.  "Solaris does it, Linux and
*BSD do not" translates into "Austin Group is welcome to take a hike".
BTW, contrary to the lovely bit of misrepresentation in that
thread of theirs ("<LWN URL> suggests that" != "someone's comment
under LWN article says it _appears_ that"), none of *BSD do it.

IMO it's a bad idea.

NAKed-by: Al Viro [off-list ref]