hammer-inodes: malloc limit exceeded

[Matthew Dillon]

:I almost forgot, but fortunately vmcore.4 contains it:
:blogbench -d0 -i1000 -o
:
:`0' is the work directory, which has nohistory flag on it.
:
:I thinks it survived for about three hours according to `last':
:reboot           ~                         Sat Dec 27 02:37
:qhwt             ttyp0    eden             Fri Dec 26 23:40 - crash  (02:56)
:reboot           ~                         Fri Dec 26 23:39

    Cool, I reproduced the issue.  It is quite interesting.  What is
    happening is that the load on HAMMER is causing the HAMMER flusher
    to get excessive deadlocks, stalling it out and preventing it from
    making any progress.  Because of that no matter how much I slow down new
    inode creation the inode count just keeps building up.

    What is really weird is that if I ^Z the blogbench and let the flusher
    catch up, then resume it, the flusher is then able to stay caught up
    for a few minutes before starting to get behind again.

    I am experimenting with a number of possible solutions, including
    having the flusher try a different inode if it hits a deadlock, to
    see if I can prevent the stall-outs.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>