Re: How to debug kern.ipc.maxpipekva ?

On Tue, 26 May 2026 19:38:59 +0300
Konstantin Belousov <kostikbel@gmail.com> wrote:

> On Tue, May 26, 2026 at 05:49:15PM +0300, Rozhuk Ivan wrote:
> > Hi!
> > 
> > 
> > I have some systems that have a lot of records in dmesg:
> > kern.ipc.maxpipekva exceeded; see tuning(7)
> > kern.ipc.maxpipekva exceeded; see tuning(7)
> > kern.ipc.maxpipekva exceeded; see tuning(7)
> > 
> > 
> > How to find out who consume all pipes memory?
> > 
> > Is it possible to add in kernel tuning to limit kern.ipc.maxpipekva
> > per process? (like done with files and threads) 
> 
> There is per-user limit RLIMIT_PIPEBUF.
> 

By default it is unlimited.

ulimits -a show as unlimited.
But on practice there is some limits:
65k per pipe of unreaded data
and ~20k pipes with unreaded data.

Where is come from?