Hi, Kirill, On Tue, Mar 12, 2019 at 10:49:51AM +0300, Kirill A. Shutemov wrote: > On Mon, Mar 11, 2019 at 05:36:58PM +0800, Peter Xu wrote: > > Hi, > > > > (The idea comes from Andrea, and following discussions with Mike and > > other people) > > > > This patchset introduces a new sysctl flag to allow the admin to > > forbid users from using userfaultfd: > > > > $ cat /proc/sys/vm/unprivileged_userfaultfd > > [disabled] enabled kvm > > CC linux-api@ > > This is unusual way to return current value for sysctl. Does it work fine > with sysctl tool? It can work, though it displays the same as "cat": $ sysctl vm.unprivileged_userfaultfd vm.unprivileged_userfaultfd = disabled enabled [kvm] > > Have you considered to place the switch into /sys/kernel/mm instead? > I doubt it's the last tunable for userfaultfd. Maybe we should have an > directory for it under /sys/kernel/mm? I haven't thought about sysfs, if that's preferred I can consider to switch to that. And yes I think creating a directory should be a good idea. Thanks, -- Peter Xu
