Re: KDevelop 5 too slow?

On Monday, 29 May 2017 10:56:10 CEST Milian Wolff wrote:
> On Saturday, May 27, 2017 3:21:56 PM CEST René J.V. Bertin wrote:
> > On Saturday May 27 2017 16:28:09 Alexander Shaduri wrote:
> > 
> > It seems it might be useful to build an AppImage for profiling purposes,
> > if
> > indeed this slowness issue is so much worse with that packaging principle
> > than with other kinds of installs.
> > 
> > I take it that the clang parser and all its requirements are bundled
> > inside
> > the AppImage too? Could it be that it does a lot of loading and seeking
> > from inside that image, and that this is what's slowing things down?
> 
> No, AppImage is just a loop-mounted image which will get it's code paged in.
> This does not explain such a slowness. Also, so far I haven't seen any
> reproducible profile that clearly shows that the AppImage build is slower
> than a distro build. But I also don't know how the AppImage code is
> compiled - Sven, Kevin - are you using Release or RelWithDebInfo for
> KDevelop and all the dependencies shippped in the AppImage?

We've used the "empty" CMake build type so far, which does *not* append `-O2 -
g -DNDEBUG`.

I've now fixed this to use the RelWithDebInfo build type:
  https://commits.kde.org/kdevelop/b810eee06655822d194f0009740c7a280c0e168c

I'll start a new build, which you can try out afterwards. You can download the 
new AppImage under the following URL, once it's done (takes approx. 2 hours):
  https://www.kdevelop.org/download -- section "Nightly builds"

Regards,
Kevin

> > I
> > don't know how those images work exactly, but if KDevelop is slower
> > running
> > from one than as/from a regular install the 1st explanation one thinks of
> > is "something related to the bundling".
> 
> Before doing such a claim, back it up with hard numbers. Profiling and
> performance isn't guess work. It's a matter of measuring and reliably
> attributing costs to specific code functions.
> 
> > > Anyway, if there's anything I can do to help you find the exact
> > > cause, I'm ready to do it.
> > 
> > What you might also try doing is to install a rolling-release distribution
> > that follows the latest KF5 versions closely in a VM, and see if you have
> > the same slowness problems that way, on the same computer. You're not by
> > any chance running from a disk that any new file you install ends up
> > scattered all over the place (or on an SSD that's equally full and hasn't
> > been TRIM'ed for a long time)?
> > 
> > R.


-- 
Kevin Funk | [email protected] | http://kfunk.org

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