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

From: Borislav Petkov
Date: Fri Oct 26 2012 - 11:34:20 EST


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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/