[systemd-devel] Excessive (virtual) memory usage of journald

[Lennart Poettering]

On Fri, 21.06.13 17:43, Holger Hans Peter Freyther (holger at freyther.de) wrote:

> 
> On Fri, Jun 21, 2013 at 05:31:13PM +0200, Holger Hans Peter Freyther wrote:
> 
> > I care about whether or not journald will work reliable on an
> > unattended system. And from what I see there is no limit in the
> > mmap cache. This means that journald can potentially exhaust the
> > virtual address space. Will it happen? I don't know, time will
> > tell.
> 
> I just read Lennart's mail and found the relevant code to limit the
> number of windows to WINDOWS_MIN (64, so 65 windows) and
> context_attach_window will put the old window in the last_unused.
> 
> The only way to allocate more windows is to have more contexts than
> WINDOWS_MIN?

Correct. Note however that hese contexts map 1:1 to the object types we
store in the journal. There are 8 object types right now, hence you only
will get 8 contexts at max. (Or with other words: this stuff is written
so that we can look at objects of different types at the same time, but
never at two objects of the same type at the same time. Which turns to
be OK for our uses, and makes things simple).

Lennart

-- 
Lennart Poettering - Red Hat, Inc.