Adding the dev list since it seems like a bug in 14.2.5. I was able to capture the output from perf top: 21.58% libceph-common.so.0 [.] ceph::buffer::v14_2_0::list::append 20.90% libstdc++.so.6.0.19 [.] std::getline<char, std::char_traits<char>, std::allocator<char> > 13.25% libceph-common.so.0 [.] ceph::buffer::v14_2_0::list::append 10.11% libstdc++.so.6.0.19 [.] std::istream::sentry::sentry 8.94% libstdc++.so.6.0.19 [.] std::basic_ios<char, std::char_traits<char> >::clear 3.24% libceph-common.so.0 [.] ceph::buffer::v14_2_0::ptr::unused_tail_length 1.69% libceph-common.so.0 [.] std::getline<char, std::char_traits<char>, std::allocator<char> >@plt 1.63% libstdc++.so.6.0.19 [.] std::istream::sentry::sentry@plt 1.21% [kernel] [k] __do_softirq 0.77% libpython2.7.so.1.0 [.] PyEval_EvalFrameEx 0.55% [kernel] [k] _raw_spin_unlock_irqrestore I increased mon debugging to 20 and nothing stuck out to me. Bryan