Comment 67 for bug 1626436

Are you guys aware of any other patches that went to mainline and may affect this? I've been hit by this issue since 4.6/4.7-ish days and can still reproduce it with 4.9.7. The two patches do help, but it's far from perfect:

4.9.7:
Startup finished in 3.498s (kernel) + 20.462s (userspace) = 23.961s

4.9.7 + https://github.com/torvalds/linux/commit/89e364db71fb5e7fc8d93228152abfa67daf35fa + https://github.com/torvalds/linux/commit/13583c3d3224508582ec03d881d0b68dd3ee8e10:
Startup finished in 3.518s (kernel) + 13.027s (userspace) = 16.546s

4.4.28:
Startup finished in 2.698s (kernel) + 11.761s (userspace) = 14.459s

There's consistently a ~second difference in kernel and another ~second in userspace. It's not a statistical error, I checked. I think it is even more pronounced in shutdown, but I don't have exact measurements from that.

(I don't use a Ubuntu kernel so I apologize for being slightly off-topic. If you're aware of an upstream issue tracking this, feel free to refer me to it.