Re: bootchart tweak ...

[Anders Norgaard <anders norgaard gmail com>]

On Thu, May 21, 2009 at 3:53 PM, Michael Meeks <michael meeks novell com> wrote:
> Hi guys,
>
>        First - thanks for the great python re-write of bootchart :-) it
> inspired me to hack it.

Great! Success! :o)

>        I attach possibly the world's most ugly hack ;-) but perhaps it is
> useful.
>
>        The aim is to allow an application to provoke boot-chart into
> separating out various sections of it's run by the insertion of a few
> simple commands. This should then help out with working out which the
> particularly slow bits are - much like Federico's scattering of the code
> with 'access' calls, and then stracing I guess :-) [ except perhaps with
> lower overhead ].
>
>        The basic idea is Rob's - and for an impl. I poked at moblin's mutter -
> adding some patch like the second attached. Essentially renaming the
> binary at certain intervals by doing:
>
>        prctl (PR_SET_NAME, "mutt-make-panel", 0, 0, 0);
>
>        (sadly it only takes 16 character names for whatever reason).
>
>        I attach a sample bootchart run of that system. This has the effect of
> making mutter appear to be separate processes.
>
>        Crack smoking ? no doubt ;-) comments much appreciated on cleaning it
> up.

Looks about as clean as can be to implement this usecase. The only
thing I wonder is if it will make sense to integrate it in
pybootchartgui (maybe behind a cmdline switch) or if it so specialized
that it is better left as something powerusers can hack in when they
need it?

>        Also (despite my lamest efforts) at reading the --help output;
> pybootchartgui managed to resist my attempts to generate an svg file -
> at least until I read the code, and discovered that -o in and of itself
> is no use without an equivalent -f option :-)
>
>        I append another patch to make that more intuitive (at least for me).

Makes a lot of sense. I'll apply this asap.

Best
Anders


>
>        HTH,
>
>                Michael.
>
> --
>  michael meeks novell com  <><, Pseudo Engineer, itinerant idiot
>
>