On Wed, Oct 30, 2013 at 10:20:52PM +0100, Jilles Tjoelker wrote: > On Wed, Oct 30, 2013 at 02:01:57PM +0100, Stefan Neudorf wrote: > > Konstantin Belousov <k...@freebsd.org> writes: > > > > Author: kib > > > Date: Mon Oct 21 16:46:12 2013 > > > New Revision: 256850 > > > URL: http://svnweb.freebsd.org/changeset/base/256850 > > > > Log: > > > Add a resource limit for the total number of kqueues available to the > > > user. Kqueue now saves the ucred of the allocating thread, to > > > correctly decrement the counter on close. > > > > Under some specific and not real-world use scenario for kqueue, it is > > > possible for the kqueues to consume memory proportional to the square > > > of the number of the filedescriptors available to the process. Limit > > > allows administrator to prevent the abuse. > > > > This is kernel-mode side of the change, with the user-mode enabling > > > commit following. > > > > Reported and tested by: pho > > > Discussed with: jmg > > > Sponsored by: The FreeBSD Foundation > > > MFC after: 2 weeks > > > > Modified: > > > head/bin/sh/miscbltin.c > > > head/etc/login.conf > > > head/lib/libc/sys/getrlimit.2 > > > head/lib/libutil/login_class.3 > > > head/lib/libutil/login_class.c > > > head/usr.bin/limits/limits.c > > > head/usr.bin/procstat/procstat_rlimit.c > > > kqueues limit isn't documented in sh(1) and limits(1) manpages. > > I can do this in the next few days. Thank you, appreciated.
>
> > > Modified: head/bin/sh/miscbltin.c
> > > ==============================================================================
> > > --- head/bin/sh/miscbltin.c Mon Oct 21 16:44:53 2013
> > > (r256849)
> > > +++ head/bin/sh/miscbltin.c Mon Oct 21 16:46:12 2013
> > > (r256850)
> > > @@ -405,6 +405,9 @@ static const struct limits limits[] = {
> > > #ifdef RLIMIT_NPTS
> > > { "pseudo-terminals", (char *)0, RLIMIT_NPTS, 1, 'p' },
> > > #endif
> > > +#ifdef RLIMIT_KQUEUES
> > > + { "kqueues", (char *)0, RLIMIT_KQUEUES, 1, 'k' },
> > > +#endif
> > > { (char *) 0, (char *)0, 0, 0, '\0' }
> > > };
> > >
>
> > I've submitted a patch to add ulimit -k (kqueue) to zsh but the reviewer
> > asked me to rename -k to -K to avoid conflict with ulimit -k (posixlocks)
> > from DragonFly. Do you anticipate FreeBSD never adds RLIMIT_POSIXLOCKS
> > support or would use incompatible option switch?
>
> > http://www.zsh.org/mla/workers/2013/msg00984.html
> > http://gitweb.dragonflybsd.org/dragonfly.git?a=search&h=HEAD&st=commit&s=posixlocks
>
> I think dragonfly has invented its own name here. The usual name for
> RLIMIT_POSIXLOCKS (Linux and Solaris) is RLIMIT_LOCKS and ulimit has it
> under -x (bash) or -L (ksh93). It seems more appropriate for FreeBSD to
> follow one of those. (On the other hand, dash ulimit has it on -w.)
The RLIMIT_LOCKS is for the fcntl(2) locks, right ? It is very strange
for me, and almost misleading, to have the limit called RLIMIT_POSIXLOCKS.
RLIMIT_LOCKS is not much telling as well, RLIMIT_FLOCK would be better
IMHO.
I agree that we better follow Linux there.
>
> Generally, the namespace for ulimit letters is very small so
> inconsistencies between shells and implementations are to be expected.
> Also, various shell implementations appear to have stopped caring to add
> new rlimits to their ulimit builtin.
>
> zsh's -N <numeric resource> option avoids the need to modify the shell
> for new rlimits, but is probably too cryptic to use other than via
> limits -e.
>
> > > Modified: head/usr.bin/limits/limits.c
> > > ==============================================================================
> > > --- head/usr.bin/limits/limits.c Mon Oct 21 16:44:53 2013
> > > (r256849)
> > > +++ head/usr.bin/limits/limits.c Mon Oct 21 16:46:12 2013
> > > (r256850)
>
> > This adds limits -e support only for sh, csh, tcsh. What about other
> > shells that already support sbsize and swapuse extensions?
>
> This can be done later; the kqueue rlimit need not be gated on it.
I definitely do not want to go over the {pd,}ksh, zsh, bash, rc and
whatever else. Somebody who cares should contact the projects and
propose the changes.
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