[9fans] lock diagnostics on Fossil server

[Lucio De Re <lucio@proxima.alt.za>]

I keep getting errors in this fashion (I'm afraid I have no serial
console, so this is manually copied stuff):

lock 0xf045c390 loop key 0xdeaddead pc 0xf017728a held by pc 0xf017728a proc 100
117: timesync pc f01ef88c dbgpc     916f     Open (Running) ut 22 st 173 bss 1b000 qpc f01c733d nl 0 nd 0 lpc f0100f6e pri 19
100:   listen pc f0100583 dbgpc     4a6a     Open (Ready) ut 165 st 1094 bss 29000 qpc f01e6bac nl 1 nd 0 lpc f01e2cb4 pri 10

The report is much less frequent now, it occurred very frequently when
I had a couple of CPU sessions running on it.  The most obvious trigger
seems to have been exportfs, I eventually turned off the stats report
I had running from the workstation and since then I have had a single
report.  While stats was running, reports seemed to coincide with full
load as reported by stats.

I've seen #I0tcpack appear in earlier reports and etherread4 beside the
more frequent exportfs.

Any idea what IO ought to be looking out for?  I have recompiled the
9pccpuf kernel from up to date sources (as up to date as replica can
make them, I was tempted to make local copies of /sys/src/9, but then I
thought I'd have to make sure the libaries are up to date too, and that
was going to be a bit of a mission.  I checked the libraries, though,
and the sizes and dates all seem to correspond with "sources" so I can
only presume there's a gremlin somewhere.

++L

PS: There's a marginal chance that dns is involved.  My Internet
connectivity isn't very robust and I note that dns gets pretty overwhelmed
when things aren't good.  It's hard to pinpoint the exact circumstances:
I don't have an active console that I can observe all the time for
unexpected reports.