Re: [Qemu-devel] [F.A.Q.] the advantages of a shared tool/kernel Git repository, tools/perf/ and tools/kvm/

[Gerd Hoffmann <kraxel@redhat.com>]

  Hi,

>> documentation:  Where the heck is the perf config file documented, other
>> than source code?  Reading the parser to figure how the config file is
>> supposed to look like really isn't fun :(
>  
>> I'm looking for a way to disable the colors in the perf report tui.  Or
>> configure them into something readable.  No, light green on light gray
>> which is used by default isn't readable.
> 
> That was fixed in 3.2-rc1, where also we have:

Very cutting edge.  /me pulls.

> [acme@felicio linux]$ cat tools/perf/Documentation/perfconfig.example

Present now, thanks.

> [colors]
> 
> 	# These were the old defaults
> 	top = red, lightgray
> 	medium = green, lightgray
> 	normal = black, lightgray
> 	selected = lightgray, magenta
> 	code = blue, lightgray

Seems to have no effect, guess the distro perf binary is too old for
that (RHEL-6).

> [tui]
> 
> 	report = off

That works.  I don't want turn off the tui altogether though, I actually
like the interactive expanding+collapsing of the call graphs.  I just
want turn off the colors.

perf_color_default_config() in util/color.c seems to lookup a "color.ui"
config variable.  Can I set that somehow?  Tried ui= in a [color]
section -- no effect.

> By default the TUI now uses whatever color is configured for your xterm,
> not something fixed as in the past, which was a common source of
> complaints, that, unfortunately I only heard indirectly :-\
> 
> Ah, if you still need to configure the colors, use "default" so that it
> will use whatever is the color configured in your
> xterm/gnome-terminal/whatever profile.
> 
> For reference, the default set of colors now is (from
> tools/perf/util/ui/browser.c):
> 
> static struct ui_browser__colorset {
>         const char *name, *fg, *bg;
>         int colorset;
> } ui_browser__colorsets[] = {
>         {
>                 .colorset = HE_COLORSET_TOP,
>                 .name     = "top",
>                 .fg       = "red",
>                 .bg       = "default",

Bad idea IMO.  Setting only one of foreground+background gives pretty
much unpredictable results.  My xterms have different background colors,
the ones with a root shell happen to have a (dark) red background.
Which results in red-on-dark-red text.  Not good.

I'd strongly suggest to either set both background and foreground to
default or to set both to a specific color.  When doing the latter make
sure the colors have enougth contrast so they are readable.

cheers,
  Gerd