[systemd-devel] Performance of systemctl status tab completion

[Lennart Poettering]

On Tue, 02.06.15 12:18, Chris Morgan (chmorgan at gmail.com) wrote:

> Hi all.
> 
> systemd 216 here on an embedded arm system, 1ghz with a load of 60% or
> more. I enabled tab completion, because I really don't like to type,
> and quickly found out that something like:
> 
> systemctl status xx<tab tab>
> 
> Takes a really long time to complete. In some cases something like 20+ seconds.
> 
> Interestingly we have systemd watchdog enabled and before increasing
> the timeout from 10 seconds to 60 seconds the system was watchdogging
> while trying to perform the tab completion operation.
> 
> I was wondering if someone knew why this was taking so long, and if
> there was some known way of resolving it. I figured that for a normal
> computer this isn't an issue, running under F21 in a mbpr parallels vm
> it takes a fraction of a second to complete the same operation, so
> maybe it isn't something that concerns normal use cases.
> 
> In any case, was wondering if someone might point me in the right direction.

Hmm, I figure we rely on some more profiling info from you to do
something about this, i.e. is this io bound or cpu bound? It would be
good to get some data from the "perf" tool for this.

But before you spend any time with this, can you recheck with a more
recent systemd version? 216 is already pretty old...

Lennart

-- 
Lennart Poettering, Red Hat