On Tue, 24 Nov 2009, Gleb Natapov wrote: > On Mon, Nov 23, 2009 at 11:30:02AM -0600, Christoph Lameter wrote: > > This adds significant overhead for the !PREEMPT case adding lots of code > > in critical paths all over the place. > I want to measure it. Can you suggest benchmarks to try? AIM9 (reaim9)? Any test suite will do that tests OS performance. Latency will also be negatively impacted. There are already significant regressions in recent kernel releases so many of us who are sensitive to these issues just stick with old kernels (2.6.22 f.e.) and hope that the upstream issues are worked out at some point. There is also lldiag package in my directory. See http://www.kernel.org/pub/linux/kernel/people/christoph/lldiag Try the latency test and the mcast test. Localhost multicast is typically a good test for kernel performance. There is also the page fault test that Kamezawa-san posted recently in the thread where we tried to deal with the long term mmap_sem issues. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
