Re: [PATCH] generic device DMA (dma_pool update)

William Lee Irwin III
2003-01-03T06:44:04Z

Adam J. Richter wrote:
>> mempool_alloc does. That's the point of it. You calculate
>> how many objects you need in order to guarantee no deadlocks and
>> reserve that number in advance (the initial reservation can fail).

On Thu, Jan 02, 2003 at 10:46:43PM -0800, David Brownell wrote:
> To rephrase that so it illustrates my point: the whole reason to
> use mempool is to try adding __GFP_NEVERFAIL when __GFP_WAIT is
> given ... because __GFP_WAIT doesn't otherwise mean NEVERFAIL.

Well, it's not quite that general. There is a constraint of the
objects allocated with a mempool having a finite lifetime. And
non-waiting mempool allocations are also available, but may fail.

So long as the queueing is fair everyone eventually gets their turn.

Bill