On Fri, Aug 30, 2013 at 8:38 AM, Sedat Dilek <sedat.di...@gmail.com> wrote: > > A Samsung series-5 ultrabook. > > $ grep "model name" /proc/cpuinfo | uniq > model name : Intel(R) Core(TM) i5-2467M CPU @ 1.60GHz
Hmm. Do you have debugging options enabled? Because that CPU should have the same core count as mine (two+HT), a slightly smaller cache (3M vs 4M) and runs at a noticeably lower frequency (1.6GHz vs 3.5). It probably also has slower memory etc, but that should still make it maybe half speed of mine. Not 1/20th. As mentioned, I get numbers in the 65M range. Yours are under 2.7M. Even with some thermal throttling, I would expect better than that. My pixel (1.8GHz i5-3427U) should be a *bit* faster that yours. And I get 54M iterations on that. I saw you mentioned CONFIG_CMPXCHG_LOCKREF=y in your .config, so you don't have spinlock debugging enabled, but maybe you have some other expensive debug option enabled. Like DEBUG_PAGEALLOC etc. If you get "perf" compiled, mind doing a perf record -f -e cycles:pp ./a.out perf report on it and look what that says? Linus -- 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/