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

[Colin Guthrie]

'Twas brillig, and Holger Hans Peter Freyther at 21/06/13 16:31 did gyre
and gimble:
> On Fri, Jun 21, 2013 at 04:19:30PM +0200, Kay Sievers wrote:
> 
>> I have no idea why you care what the journald process does with its
>> very own 2+GB of address space, and why it uses 128MB of it.
> 
> 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.

Did you read Lennart's reply?

There is a limit to the mmap cache. There are only so many windows that
are used (64) and when that limit is reached, the old, less used windows
are thrown away and reallocated.

I can also assure you that when there was a bug in this cache window
code about eight months ago it was quite obvious. This was fixed
(http://cgit.freedesktop.org/systemd/systemd/commit/?id=89de694724f376a6852e879fe987e7e531327654)
and since that time I've been running several different unattended
journals and don't have any issues.


 16:40:55 up 45 days, 20:12,  1 user,  load average: 0.13, 0.07, 0.10
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root       418  0.0  0.2 306028 10284 ?        Ss   May06  12:34
/usr/lib/systemd/systemd-journald

Col



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Colin Guthrie
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