more examples of rampant OSD memory consumption:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
COMMAND
1326773 ceph 20 0 11.585g 0.011t 34728 S 110.3 8.6 14:26.87
ceph-osd
204622 ceph 20 0 16.414g 0.015t 34808 S 100.3 12.5 17:53.36
ceph-osd
5706 ceph 20 0 5235600 4.248g 32488 S 11.6 3.4 19:42.63
ceph-osd
5709 ceph 20 0 10.453g 9.709g 32380 S 3.6 7.7 44:51.29
ceph-osd
5826 ceph 20 0 5242920 4.245g 32408 S 2.0 3.4 17:27.84
ceph-osd
5705 ceph 20 0 5252192 4.264g 32340 S 1.7 3.4 24:06.11
ceph-osd
5716 ceph 20 0 5440428 4.436g 32556 S 1.7 3.5 24:05.89
ceph-osd
5720 ceph 20 0 5359888 4.359g 32592 S 1.7 3.5 17:18.63
ceph-osd
5836 ceph 20 0 5081448 4.099g 32468 S 1.7 3.3 16:56.52
ceph-osd
OSD memory usage in the high-teens seems to be common across all hosts.