On Fri, Nov 22, 2024 at 3:57 AM Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx> wrote: > > On Thu, Nov 21, 2024 at 02:00:46AM +0000, Matthew Wilcox wrote: > > On Wed, Nov 20, 2024 at 02:10:44PM -0800, Shakeel Butt wrote: > > > If 'struct vm_area_struct' is prone to performance issues due to > > > cacheline misalignments then we should do something about the > > > __randomize_layout tag for it. I imagine we can identify the fields > > > which might be performance critical to be on same cacheline or different > > > cacheline due to false sharing then we can divide the fields into > > > different cacheline groups and fields can be __randomize_layout within > > > the group. WDYT? > > > > Pretty sure the people who think security is more important than > > performance are the only ones who randomize structs. > > I agree that I don't think we need concern ourselves with users of this > setting for precisely this reason. > > I wouldn't want supporting this to cause difficulty for users who do not > enable this when those who do aren't really concerned about the perf issues > as Matthew says. Ack. Will keep it as is. Thanks!
