On Fri, Jun 08, 2007 at 01:12:00PM -0700, Keshavamurthy, Anil S wrote: > The resource pool indeed provide extra robustness, the initial pool size will > be equal to min_count + grow_count. If the pool object count goes below > min_count, then pool grows in the background while serving as emergency > pool with min_count of objects in it. If we run out of emergency pool objects > before the pool grow in the background, then we go to OS for allocation. > > Similary, if the pool objects grows above the max threshold, > the objects are freed to OS in the background thread maintaining > the pool objects close to min_count + grow_count size.
slab already has this and it has additional functionalities like reaping over time, when there is no activity... > We need several objects of size say( 4 * sizeof(u64)) and reuse > them in dma map/unmap api calls for managing io virtual allocation address > that > this driver has dished out. Hence having pool of objects where we put > the element in the linked list and and get it from the linked list is pretty > fast compared to slab. Not sure how is this fast compared to slab. Atleast slab is lockless in the fast case.. > We had this kmem_cache_alloc() with mempool concept earlier and Andi suggest > to > come up with something pre-allocated pool. > Andi, Can you chime in please. In the initial patches, only for iova we were using slabs + mempool. But for others like pgtable_mempool, we were using simple mempools. Even slabs + mempool is not same as just usng slab.. slab is lockless for the fast case. thanks, suresh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
