DNOTIFY support and some timing

[Lubos Lunak]

On Sunday 23 of February 2003 22:56, Josef Weidendorfer wrote:
> On Sunday 23 February 2003 15:07, Christian Esken wrote:
> > Hello,
> >
> > is there a good reason not to compile in DNOTIFY support by default?
> > The code in kio/kio/kdirwatch.cpp already checks the kernel version.
> > I agree, that there should be a possibility do --disable-dnotify ,
> > but default should be enabled.
>
> I agree.
>
> > For example SuSE8.1 (ships Kernel 2.4.19 and KDE3.0) has
> > not compiled KDE with "--enable-dnotify".
>
> Hmm. That's not our problem, though.
> Doesn't SuSE use FAM with DNOTIFY? This way, KDE programs should never need
> to do polling at all...

 Yes, SuSE's FAM has dnotify support in it.

> > AFAIK KDE3.0 already had dnotify support?!?
> >
> >
> > Remark: I came across this, while working on a list of tips on how to
> > use KDE3 on slow computers. On "low end" computers like mine
> > (PIII - 450Mhz, 128MB Ram) doing polling has MAJOR impact on
> > overall KDE performance. Application startup and overall resposiveness
> > is much better with DNOTIFY. I blame this on the continuous task
> > switching from and to kded.

 On my old K6/188, without FAM/DNOTIFY, I have a permanent 10% CPU usage just 
because of the polling.

[snip]
>
> I don't understand how 0,5 seconds poll interval can make such a bad
> behaviour. OK, kded watches around 40 directories. We should switch to
> VFolders and get only a few dirs to watch for kded...

 It's not 40 directories. SuSE has quite large directory structure under 
/etc/opt/kde3, so there are more than 200 directories checked.

>
> You can change the STAT polling interval in global KDE config
> (.kde/share/config/kdeglobals) to e.g. 2 secs:
> [DirWatch]
> PollInterval=2000

-- 
Lubos Lunak
KDE developer
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