On Tue, Oct 29, 2019 at 05:27:43PM +0000, Edgecombe, Rick P wrote: > On Mon, 2019-10-28 at 22:00 +0100, Peter Zijlstra wrote: > > That should be limited to the module range. Random data maps could > > shatter the world. > > BPF has one vmalloc space allocation for the byte code and one for the module > space allocation for the JIT. Both get RO also set on the direct map alias of > the pages, and reset RW when freed. Argh, I didn't know they mapped the bytecode RO; why does it do that? It can throw out the bytecode once it's JIT'ed. > You mean shatter performance? Shatter (all) large pages.
