Re: [PATCH] net: core: page_pool: add user refcnt and reintroduce page_pool_destroy

From: Jesper Dangaard Brouer
Date: Tue Jul 02 2019 - 10:52:41 EST


On Tue, 2 Jul 2019 17:44:27 +0300
Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> wrote:

> On Tue, Jul 02, 2019 at 04:31:39PM +0200, Jesper Dangaard Brouer wrote:
> >From: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
> >
> >Jesper recently removed page_pool_destroy() (from driver invocation) and
> >moved shutdown and free of page_pool into xdp_rxq_info_unreg(), in-order to
> >handle in-flight packets/pages. This created an asymmetry in drivers
> >create/destroy pairs.
> >
> >This patch add page_pool user refcnt and reintroduce page_pool_destroy.
> >This serves two purposes, (1) simplify drivers error handling as driver now
> >drivers always calls page_pool_destroy() and don't need to track if
> >xdp_rxq_info_reg_mem_model() was unsuccessful. (2) allow special cases
> >where a single RX-queue (with a single page_pool) provides packets for two
> >net_device'es, and thus needs to register the same page_pool twice with two
> >xdp_rxq_info structures.
>
> As I tend to use xdp level patch there is no more reason to mention (2) case
> here. XDP patch serves it better and can prevent not only obj deletion but also
> pool flush, so, this one patch I could better leave only for (1) case.

I don't understand what you are saying.

Do you approve this patch, or do you reject this patch?

--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer