Re: [GIT PULL 0/9] perf/core improvements and fixes

[Borislav Petkov <bp@alien8.de>]

On Sat, Oct 27, 2012 at 12:31:42AM +0900, Namhyung Kim wrote:
> And I see a strange delay when compiling builtin-sched.o.  After
> building perf tools, I deleted builtin-{sched,test,script}.o to rebuild
> the only since they are largest ones.
> 
>   namhyung@leonhard:perf$ ls -lS *.c | head -3
>   -rw-r--r-- 1 namhyung namhyung 45522 2012-10-27 00:20 builtin-sched.c
>   -rw-r--r-- 1 namhyung namhyung 36372 2012-10-27 00:20 builtin-test.c
>   -rw-r--r-- 1 namhyung namhyung 35555 2012-10-27 00:20 builtin-script.c
> 
>   namhyung@leonhard:perf$ rm builtin-{sched,test,script}.o
> 
> 
> And then building each file with time command shows this:
> 
>   namhyung@leonhard:perf$ time make builtin-script.o &> /dev/null
> 
>   real	0m4.577s
>   user	0m2.755s
>   sys	0m1.655s
> 
>   namhyung@leonhard:perf$ time make builtin-test.o &> /dev/null
> 
>   real	0m4.486s
>   user	0m2.707s
>   sys	0m1.658s
> 
>   namhyung@leonhard:perf$ time make builtin-sched.o &> /dev/null
> 
>   real	0m16.936s
>   user	0m15.157s
>   sys	0m1.635s
> 
> You can see it easily when building perf without -j option. But I have
> no idea why it takes so long..

Well, you can trace that workload with perf itself, no, and see the
hotspots.

:-)

-- 
Regards/Gruss,
Boris.