On Mon, Apr 21, 2014, at 12:26 AM, Shawn K. Quinn wrote: > With a tmpfs mounted on /tmp: > > $ cd /tmp > $ dd if=/dev/zero of=0 bs=1M ; sync ; sleep 5 ; rm 0 > > results in dmesg getting spammed with: > > uao_flush: strange, got an out of range flush (fixed)
Forgot to mention, this is on amd64 with a recent snapshot. > If the tmpfs is large enough (larger than physical RAM, maybe?) another > error happens (I don't have it handy right now) That error would be: pagedaemon: wait_pla deadlock detected! Screenshots of ddb info available temporarily at: http://www.shawnkquinn.com/openbsd-tmpfs-crash/ (Some may be duplicates, a couple may have a small part of the screen cut off. Enough should be legible to figure out what's going on.) > and the system usually > winds up wedged badly enough that "boot dump" from ddb won't work as > designed. I can reproduce this on request. Also, it should be noted tmpfs allocates the entire amount of memory available by default. When I do something similar with mfs, I can write at least an 8G file to a 10G mfs disk, and the system does not actually crash. It does slow down and the load average skyrockets (8.25 right after killing dd) but the system never becomes unusable. -- Shawn K. Quinn [email protected]
