Em Sat, Jul 20, 2013 at 12:57:27AM +0900, Hitoshi Mitake escreveu: > At Thu, 18 Jul 2013 15:43:18 -0700, Andi Kleen wrote: > > glibc calloc() has an optimization to not explicitely memset() > > very large calloc allocations that just came from mmap(), > > because they are known to be zero.
> > This could result in the perf memcpy benchmark reading only from > > the zero page, which gives unrealistic results. > > Always call memset explicitly on the source area to avoid this problem. > > +++ b/tools/perf/bench/mem-memcpy.c > > @@ -115,8 +115,10 @@ static void alloc_mem(void **dst, void **src, size_t > > length) > > *src = zalloc(length); > > - if (!src) > > + if (!*src) > In the latest mem-memcpy.c, this if (!src) is already fixed as if > (!*src). This modification makes applying fail. I fixed this up, please take a look at: https://git.kernel.org/cgit/linux/kernel/git/acme/linux.git/commit/?h=perf/core&id=a198996c7afae0097c67a61851f19863e59697b2 https://git.kernel.org/cgit/linux/kernel/git/acme/linux.git/log/?h=perf/core - Arnaldo -- 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/
