akonadi and CPU

[Daniel Vrátil]

On Monday, March 27, 2017 11:14:13 PM CEST René J.V. Bertin wrote:
> On Saturday March 25 2017 07:46:02 Pablo Sanchez wrote:
> > Hi Rene,
> > 
> > During the event, what is the process consuming CPU?  Or processes?
> 
> These four, roughly in order of CPU usage:
> 
> dbus-daemon

This is KDEPIM4, so metric tonn of messages goes through DBus. Blame crappy 
DBus implementation :-)

Mostly gone in KF5 as change notifications has been migrated to the binary 
protocol.

> akonadi_imap_agent

That's the guy checking your emails. It needs to parse all the downloaded 
messages and then do a bunch of checks to know if they are new ones or 
existing ones, which takes some CPU. There are places for improvement, 
definitely. Like for instance not parsing the message body, because all we need 
to know is in the headers....

> mysqld

I'll save you the work of running the SQL debugging as Pablo requested and 
just say that yup, we are still running those expensive SQL queries. KDEPIM4 
was even worse at this than KF5.

> akonadiserver

There's some parsing and processing going on, that needs some CPU too. Again, 
master is much better as the expensive text protocol parsing is gone as well 
as the overhead from DBus.

> 
> dbus-daemon can go as high as 80%, the imap agent and mysqld hover around
> 45% while akonadiserver is somewhat less expensive. Together they use a
> good chunk of resources on my 2 core * 2 hyperthreads i7, what with all the
> IPC going on.

DBus was the killer in KDE4. Nowadays it's out of the game, but we still suck 
at not doing lots of useless SQL queries. One day, maybe, I'll get to fix it 
:-)


Dan

> 
> R.


-- 
Daniel Vrátil
www.dvratil.cz | dvratil at kde.org
IRC: dvratil on Freenode (#kde, #kontact, #akonadi, #fedora-kde)

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