On Thu, Apr 17, 2014 at 11:35:26AM -0400, Theodore Ts'o wrote: > So I've been thinking about this some more, and it seems to me is > actually, what we need is *both* an LRU and a RR scheme. We already have shrinker implementations that do this. It would probably take 10-15 lines of code to add it to any existing LRU list based shrinker..... > The real problem here is that we have workloads that are generating a > large number of "low value" extent cache entries. That is, they are > extremely unlikely to be used again, because they are small, and being > generated when you have a highly fragmented extent status cache, and > very often, the workload is a random read/write workload, so there is > no way the full "working set" of extent cache entries could be kept in > memory at the same time anyway. These less valuable cache entries are > being generated at a very high rate, and we want to make sure we don't > penalize the "valuable" cache entries. Yup, an "object referenced" bit that gets set on a cache lookup hit. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
