Re: [PATCH] dmapool: push new blocks in ascending order

From: Keith Busch
Date: Tue Feb 21 2023 - 13:08:04 EST


On Tue, Feb 21, 2023 at 10:02:34AM -0800, Christoph Hellwig wrote:
> On Tue, Feb 21, 2023 at 08:54:00AM -0800, Keith Busch wrote:
> > From: Keith Busch <kbusch@xxxxxxxxxx>
> >
> > Some users of the dmapool need their allocations to happen in ascending
> > order. The recent optimizations pushed the blocks in reverse order, so
> > restore the previous behavior by linking the next available block from
> > low-to-high.
>
> Who are those users?
>
> Also should we document this behavior somewhere so that it isn't
> accidentally changed again some time in the future?

usb/chipidea/udc.c qh_pool called "ci_hw_qh". My initial thought was dmapool
isn't the right API if you need a specific order when allocating from it, but I
can't readily test any changes to that driver. Restoring the previous behavior
is easy enough.