On Fri, Oct 26, 2012 at 5:31 PM, Namhyung Kim <namhy...@kernel.org> wrote: > 2012-10-26 (금), 09:06 -0600, David Ahern: >> On 10/26/12 8:54 AM, Ingo Molnar wrote: >> >> perf/core improvements: >> >> >> >> . perf inject changes to allow showing where a task sleeps, from Andrew >> >> Vagin. >> >> >> >> . Makefile improvements from Namhyung Kim. >> > >> > These are really useful: there used to be a couple of seconds of >> > wait time at the beginning of every perf build - these are now >> > nicely explained with the various CHK entries. > > Kudos to Jiri who did the real work! > >> >> PERF-VERSION-GEN and specifically the git commands are the cause of more >> delay than the config checks, especially when doing the build in a VM >> with the kernel source on an NFS mount. > > 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. > Yes, I see that delay on copiling builtin-sched.c on my IVB system. Don't know why it takes a significant number of seconds to compile this file. It did not use to be like that a few revisions back. It takes about 8 seconds on my OC'd IVB (> 4GHz). I don't see much code in that file.
> 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.. > > Thanks, > Namhyung > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/