dev.bce.3.mbuf_alloc_failed_count increases permanently

[David Christensen]

> sysctl -a | g bce.3|g -vE '(%|stat)'; echo; sleep 10;  sysctl -a | g bce.3|
> g -vE '(%|stat)'; echo; netstat -m
> 
> dev.bce.3.l2fhdr_error_count: 0
> dev.bce.3.mbuf_alloc_failed_count: 2098854
> dev.bce.3.mbuf_frag_count: 2655285
> dev.bce.3.dma_map_addr_rx_failed_count: 0
> dev.bce.3.dma_map_addr_tx_failed_count: 57
> dev.bce.3.unexpected_attention_count: 0
> dev.bce.3.com_no_buffers: 0
> 
> dev.bce.3.l2fhdr_error_count: 0
> dev.bce.3.mbuf_alloc_failed_count: 2098856
> dev.bce.3.mbuf_frag_count: 2655288
> dev.bce.3.dma_map_addr_rx_failed_count: 0
> dev.bce.3.dma_map_addr_tx_failed_count: 57
> dev.bce.3.unexpected_attention_count: 0
> dev.bce.3.com_no_buffers: 0
> 
> 
> Any suggestions? What is the reason of this?

It's normal in a system under load, the kernel can't always
allocate memory when requested by the driver.  The result
is that RX frames will be dropped as the driver reuses an
existing mbuf, a response taken by many other drivers.

If you notice rapid increases during certain system operations
then you should consider increasing the amount of system
memory.

Dave