LSMPI - Linux Shared Memory Punt Interface - memory pool is being used to transfer packets/messages from the forwarding processor to the route processor. This memory pool is carved at router initialization into pre-allocated buffers, as opposed to the Processor pool where IOSXE can allocate memory blocks dynamically.
It is therefore expected to see this low amount of free memory in lsmpi_io. In fact, it would be more of a concern to see a large amount of free memory for that pool as it would mean IOSXE wasn't able to allocate that memory.
Also, examining show buffers and the lsmpi_rx and lsmpi_tx secions, we can see that the free buffers counters are 0.
Private particle pools:
lsmpi_rx buffers, 416 bytes (total 8194, permanent 8194):
0 in free list (8194 min, 8194 max allowed)
8194 hits, 0 misses
8194 max cache size, 0 in cache
3316582 hits in cache, 0 misses in cache
lsmpi_tx buffers, 416 bytes (total 4098, permanent 4098):
0 in free list (4098 min, 4098 max allowed)
4098 hits, 0 misses
4098 max cache size, 4089 in cache
1952353 hits in cache, 0 misses in cache
If your snmp application is polling this memory or pool statistics, it will generate false positive alerts. It would therefore be better to discontinue polling the lsmpi_io pool or lsmpi buffers.