From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: <netdev@vger.kernel.org>, <davem@davemloft.net>,
<kernel-team@fb.com>, <ilias.apalodimas@linaro.org>,
brouer@redhat.com, Brendan Gregg <brendan.d.gregg@gmail.com>
Subject: Re: [net-next PATCH] page_pool: do not release pool until inflight == 0.
Date: Tue, 12 Nov 2019 16:11:45 +0100 [thread overview]
Message-ID: <20191112161145.68d2dbd2@carbon> (raw)
In-Reply-To: <20191112053210.2555169-1-jonathan.lemon@gmail.com>
On Mon, 11 Nov 2019 21:32:10 -0800
Jonathan Lemon <jonathan.lemon@gmail.com> wrote:
> The page pool keeps track of the number of pages in flight, and
> it isn't safe to remove the pool until all pages are returned.
>
> Disallow removing the pool until all pages are back, so the pool
> is always available for page producers.
>
> Make the page pool responsible for its own delayed destruction
> instead of relying on XDP, so the page pool can be used without
> xdp.
>
> When all pages are returned, free the pool and notify xdp if the
> pool is registered with the xdp memory system. Have the callback
> perform a table walk since some drivers (cpsw) may share the pool
> among multiple xdp_rxq_info.
>
> Fixes: d956a048cd3f ("xdp: force mem allocator removal and periodic warning")
> Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
FYI: I'm using this work-in-progress bpftrace script to test your patch:
https://github.com/xdp-project/xdp-project/blob/master/areas/mem/bpftrace/page_pool_track_shutdown01.bt
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
prev parent reply other threads:[~2019-11-12 15:12 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-12 5:32 [net-next PATCH] page_pool: do not release pool until inflight == 0 Jonathan Lemon
2019-11-12 12:08 ` Jesper Dangaard Brouer
2019-11-12 16:33 ` Jonathan Lemon
2019-11-12 16:48 ` Jesper Dangaard Brouer
2019-11-12 17:14 ` Jonathan Lemon
2019-11-12 17:23 ` Alexei Starovoitov
2019-11-12 17:32 ` Jonathan Lemon
2019-11-13 10:08 ` Jesper Dangaard Brouer
2019-11-13 16:37 ` Jesper Dangaard Brouer
2019-11-12 15:11 ` Jesper Dangaard Brouer [this message]
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