How to identify if my innodb buffer pool is choking ? (and should i increase it ?)

We have a mysql box where i do rigorous scans/aggregations every few minutes (~ 35GB of data). Innodb buffer pool is ~ 1.5GB.

Off late i have started noticing a开发者_开发知识库 few latent queries, where the 'read innodb pages' metric has started to spike up.

Am speculating innodb buffer pool size is the culprit here. Which metric should i refer to confirm that my buffer pool is choking.

Thanks