Thanks! Waited a little bit before doing this because: a) we applied a mitigation (changing tunable default) which made bug 917224 far less likely; b) it was less likely on 2.1.x anyway; c) 2.1.x is shadowed in ~arch so it gets less testing. But it should be good to go now.
amd64 done
ppc64 done
arm64 done all arches done