RE: [EXT] Re: [PATCH v2 00/22] add Object Storage Media Pool (mpool)

From: Nabeel Meeramohideen Mohamed (nmeeramohide)
Date: Wed Oct 21 2020 - 13:11:03 EST


On Tuesday, October 20, 2020 3:36 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
>
> What does Linux get from merging mpool?
>

What Linux gets from merging mpool is a generic object store target with some
unique and beneficial features:

- the ability to allocate objects from multiple classes of media
- facilities to memory-map (and unmap) collections of related objects with similar
lifetimes in a single call
- proactive eviction of object data from the page cache which takes into account
these object relationships and lifetimes
- concurrent access to object data directly and memory mapped to eliminate
page cache pollution from background operations
- a management model that is intentionally patterned after LVM so as to feel
familiar to Linux users

The HSE storage engine, which is built on mpool, consistently demonstrates
throughputs and latencies in real-world applications that are multiples better
than common alternatives. We believe this represents a concrete example of
the benefits of the mpool object store.

That said, we are very open to ideas on how we can improve the mpool
implementation to be better aligned with existing Linux I/O mechanisms.

Thanks,
Nabeel