On Thu, 28 Sep 2017 14:29:02 +0200 Laurent Dufour <lduf...@linux.vnet.ibm.com> wrote:
> > Laurent's [0/n] provides some nice-looking performance benefits for > > workloads which are chosen to show performance benefits(!) but, alas, > > no quantitative testing results for workloads which we may suspect will > > be harmed by the changes(?). Even things as simple as impact upon > > single-threaded pagefault-intensive workloads and its effect upon > > CONFIG_SMP=n .text size? > > I forgot to mention in my previous email the impact on the .text section. > > Here are the metrics I got : > > .text size UP SMP Delta > 4.13-mmotm 8444201 8964137 6.16% > '' +spf 8452041 8971929 6.15% > Delta 0.09% 0.09% > > No major impact as you could see. 8k text increase seems rather a lot actually. That's a lot more userspace cacheclines that get evicted during a fault... Is the feature actually beneficial on uniprocessor?