| This is a buffer pool analysis message that states that the Ethernet packet
buffer pool is down to its last buffer. The "Hog" field lists the Program
Counter of the routine holding the most buffers, and the number it holds; in
this case, it is a null PC, and 16 buffers have this PC. The "NoPC" field lists
the number of allocated buffers which are not held by any routine. The "Free"
field lists the number of available buffers remaining. The purpose of buffer
pool analysis is to try and identify routines which are not properly releasing
resources when a low-resource condition occurs. The buffer pool is a fixed-size
resource.
This would explain why the 900TM was not reachable via Ethernet, all the
Ethernet receive buffers were in use (or lost, as implied by the null PC
values). Therefore, it was unable to process further incoming traffic. Resetting
the module reset the buffer pool to its initial state, with no buffers allocated.
That explains the message and why the repeater was no longer communicating, but
does not explain how it got into this state. However, I do not believe this
would hang the repeater ports, they should continue repeating on a bit-by-bit
basis. The repeater MAC receives whole Ethernet packets, which then go into the
buffer pool for processing.
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| Difficult to say. It could be related to the pattern of Ethernet traffic (maybe
there was a long burst of broadcasts, or management packets destined for that
MAC, etc. that consumed all the buffers at once before any could be freed). On
the other hand, perhaps some faulty Ethernet hardware on the module was
generating false receptions; this is pure speculation, since I am only familiar
with the firmware, not the hardware.
I would say this is a pretty unusual problem. The repeater normally ought to be
able to keep up with MAC traffic, unless something has the CPU so tied up that
it can't do anything beyond respond to interrupts and queue the packets for
later service. More information would be necessary to isolate it, which means it
would have to happen again to be able to tell anything.
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