On Thu, 14 Sep 2017 22:14:46 +0900 Minchan Kim <minchan@xxxxxxxxxx> wrote: > > Now. Users can choose between VMA based readahead and original > > readahead via a knob as follow at runtime, > > > > /sys/kernel/mm/swap/vma_ra_enabled > > It's not a config option and is enabled by default. IOW, it's under the radar > so current users cannot notice it. That's why we want to emit big fat warnning. > when old user set 0 to page-cluster. However, as Andrew said, it's lame. > > If we make it config option, product maker/kernel upgrade user can have > a chance to notice and read description so they could be aware of two weird > knobs and help to solve the problem in advance without printk_once warn. > If user has no interest about swap-readahead or skip the new config option > by mistake, it works physcial readahead which means no regression. Yup, a Kconfig option sounds like a good idea. And that's a bit more friendly to tiny kernels as well. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
