Re: A Plumber’s Wish List for Linux

[Andi Kleen <andi@firstfloor.org>]

Kay Sievers <kay.sievers@vrfy.org> writes:
>
> * allow changing argv[] of a process without mucking with environ[]:
> Something like setproctitle() or a prctl() would be ideal. Of course
> it

prctl(PR_SET_NAME, ...)

The only problem is that some programs still use argv[] and get the old
name, but at least it works in "top"

> * An auxiliary meta data message for AF_UNIX called SCM_CGROUPS (or
> something like that), i.e. a way to attach sender cgroup membership to
> messages sent via AF_UNIX.

The problem is: this requires a reference count and these reference
counts can be very expensive. We had the same problem with pid
namespaces ruining AF_UNIX performance in some cases.

It can be probably done, but one would need to be very careful
about scalability issues.


> * SCM_COMM, with a similar use case as SCM_CGROUPS. This auxiliary
> control message should carry the process name as available
> in /proc/$PID/comm.

That sounds super racy. No guarantee at all this is unique and useful
for anything and everyone can change it.

The other ideas mostly sound reasonable to me, but I haven't thought
a lot about their details and implications.

-Andi


-- 
ak@linux.intel.com -- Speaking for myself only