Re: [rfc v2 3/6] dma-pool: dynamically expanding atomic pools

From: David Rientjes
Date: Tue Apr 14 2020 - 15:31:37 EST


On Tue, 14 Apr 2020, Christoph Hellwig wrote:

> > I'll rely on Christoph to determine whether it makes sense to add some
> > periodic scavening of the atomic pools, whether that's needed for this to
> > be merged, or wheter we should enforce some maximum pool size.
>
> I don't really see the point. In fact the only part of the series
> I feel uneasy about is the growing of the pools, because it already
> adds a fair amount of complexity that we might not need for simple
> things, but shrinking really doesn't make any sense. So I'm tempted
> to not ever support shrinking, and even make growing optional code under
> a new config variable. We'll also need a way to query the current size
> through e.g. a debugfs file.
>

New debugfs file sounds good, I'll add it. If we want to disable dynamic
expansion when the pool is depleted under a new config option, let me
know.