Re: [PATCH] sunrpc: replace large table of slots with mempool

[Martin Wilck <martin.wilck@ts.fujitsu.com>]

NeilBrown wrote:

> I think I would still recommend using mempools as they are a well tested
> and understood concept.
> I think the key difference that you are proposing is that instead of
> a single mempool with 256 slots preallocated, we have a separate mempool
> for each client with 4 slots preallocated.
> I think that would be a good change.  The 'struct mempool_s' isn't very
> large, only about 8 pointers, so havng them per-client is not a big cost.

You also need to create a slab cache for each client - /proc/slabinfo 
could grow quite a bit.

How about mempool_resize()? We could have a single pool and increase it 
by 4 for every new client. I would prefer to avoid shrinking the pool 
when connections are terminated, though. Thus it might be best to track 
the number of simultaneously active clients and increase the pool when 
it increases above the previous maximum value.

Martin

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Dr. Martin Wilck
PRIMERGY System Software Engineer
x86 Server Engineering

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