Re: perf: confused by cc1

[Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>]

Dr. David Alan Gilbert wrote:
> Hi,
>   I'm running 2.6.33rc2 and thought I'd have a play with perf; its
> symbol resolution code seems to be getting itself a bit confused however:
> 
> I recorded a trace of a kernel build like so:
> 
>  sudo /discs/more/git/linux-2.6/tools/perf/perf record -a -e cycles -i -g -v -s -d make -j 8 bzImage
> 
> Then I did:
> /discs/more/git/linux-2.6/tools/perf/perf report -g
> 
> and the top entry is:
> 
>     69.89%              cc1  cc1                                                      [.] 0x000000000337cd
>                         |          
>                         |--0.99%-- 0x9f5da8
>                         |          
>                         |--0.74%-- 0x9eec95
>                          --98.27%-- [...]
> 
> but it's refusing to do symbol look up for cc1 even if I install
> the (ubuntu) debug packages (most other files it is doing
> symbol resolution on where they have it). I dug a bit further and
> it looks like it's not trying to look up the debug packages for cc1
> because it think that mapping is a kernel map.  Also for some reason it
> thinks the cc1 is an overlapping mapping with the gcc4 binary it's been
> executed from:
> 

Your kernel is relocatable? See: http://lkml.org/lkml/2009/12/29/358

Thanks,
Xiao