Hi, this is a request to please include upstream commit 00df35f991914db6b8bde8cf09808e19a9cffc3d ("cpu: Defer smpboot kthread unparking until CPU known to scheduler") in stable trees >= 3.15 and < 4.1. Upstream dd9d3843755da95f63dd3a376f62b3e45c011210 ("sched: Fix cpu_active_mask/cpu_online_mask race") was included in stable to fix a race condition that led to kthreads running on the wrong cpu and causing errors like "kernel BUG at kernel/smpboot.c:135!". This is especially likely when running as a virtualized guest. However, the fix depends on the ordering introduced in the requested patch, so the issue remains in kernels between 3.15 when the bug was introduced, and 4.1 which has 00df35f9. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html