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Date: Wed, 3 Jan 2024 11:04:11 +0100
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Cc: stable@vger.kernel.org, patches@lists.linux.dev,
	Somnath Kotur <somnath.kotur@broadcom.com>,
	Michael Chan <michael.chan@broadcom.com>,
	David Wei <dw@davidwei.uk>, Jakub Kicinski <kuba@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 6.6 055/156] bnxt_en: do not map packet buffers twice
Message-ID: <2024010348-headroom-plating-1e2a@gregkh>
References: <20231230115812.333117904@linuxfoundation.org>
 <20231230115814.135415743@linuxfoundation.org>
 <ZZQqGtYqN3X9EuWo@C02YVCJELVCG.dhcp.broadcom.net>
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In-Reply-To: <ZZQqGtYqN3X9EuWo@C02YVCJELVCG.dhcp.broadcom.net>

On Tue, Jan 02, 2024 at 10:22:02AM -0500, Andy Gospodarek wrote:
> On Sat, Dec 30, 2023 at 11:58:29AM +0000, Greg Kroah-Hartman wrote:
> > 6.6-stable review patch.  If anyone has any objections, please let me know.
> > 
> 
> No objections from me.
> 
> For reference I do have an implementation of this functionality to v6.1
> if/when it should be added.   It is different as the bnxt_en driver did
> not use the page pool to manage DMA mapping until v6.6.
> 
> The minimally disruptive patch to prevent this memory leak is below:
> 
> >From dc82f8b57e2692ec987628b53e6446ab9f4fa615 Mon Sep 17 00:00:00 2001
> From: Andy Gospodarek <andrew.gospodarek@broadcom.com>
> Date: Thu, 7 Dec 2023 16:23:21 -0500
> Subject: [PATCH] bnxt_en: unmap frag buffers before returning page to pool
> 
> If pages are not unmapped before calling page_pool_recycle_direct they
> will not be freed back to the pool.  This will lead to a memory leak and
> messages like the following in dmesg:
> 
> [ 8229.436920] page_pool_release_retry() stalled pool shutdown 340 inflight 5437 sec
> 
> Fixes: a7559bc8c17c ("bnxt: support transmit and free of aggregation buffers")
> Signed-off-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
> ---
>  drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 7 +++++++
>  1 file changed, 7 insertions(+)

I do not understand, what is this patch for?

Why not submit it for normal inclusion first?

confused,

greg k-h