Hi Daniel, On Tue, Nov 05, 2019 at 08:41:18AM -0800, Daniel Colascione wrote: > On Tue, Nov 5, 2019 at 8:24 AM Andrea Arcangeli <aarcange@xxxxxxxxxx> wrote: > > The long term plan is to introduce UFFD_FEATURE_EVENT_FORK2 feature > > flag that uses the ioctl to receive the child uffd, it'll consume more > > CPU, but it wouldn't require the PTRACE privilege anymore. > > Why not just have callers retrieve FDs using recvmsg? This way, you > retrieve the message packet and the file descriptor at the same time > and you don't need any appreciable extra CPU use. I don't follow you here. Can you elaborate on how recvmsg would be used in this case? -- Sincerely yours, Mike.