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From: "Gan, Yi Fang" <yi.fang.gan@intel.com>
To: Andrew Lunn <andrew@lunn.ch>
CC: Russell King <linux@armlinux.org.uk>, Heiner Kallweit
	<hkallweit1@gmail.com>, "David S . Miller" <davem@davemloft.net>, "Eric
 Dumazet" <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni
	<pabeni@redhat.com>, =?iso-8859-1?Q?Marek_Beh=FAn?= <kabel@kernel.org>,
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	<linux-kernel@vger.kernel.org>, "Looi, Hong Aun" <hong.aun.looi@intel.com>,
	"Voon, Weifeng" <weifeng.voon@intel.com>, "Song, Yoong Siang"
	<yoong.siang.song@intel.com>, "Choong, Yong Liang"
	<yong.liang.choong@intel.com>
Subject: RE: [PATCH net v3 1/1] net: phylink: Add module_exit()
Thread-Topic: [PATCH net v3 1/1] net: phylink: Add module_exit()
Thread-Index: AQHaPvcS48imAJYtYkO0dKGHM8Fni7DJn3IAgAqTrIA=
Date: Thu, 11 Jan 2024 06:38:58 +0000
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> -----Original Message-----
> From: Andrew Lunn <andrew@lunn.ch>
> Sent: Thursday, January 4, 2024 9:05 PM
> To: Gan, Yi Fang <yi.fang.gan@intel.com>
> Cc: Russell King <linux@armlinux.org.uk>; Heiner Kallweit
> <hkallweit1@gmail.com>; David S . Miller <davem@davemloft.net>; Eric
> Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo
> Abeni <pabeni@redhat.com>; Marek Beh=FAn <kabel@kernel.org>;
> netdev@vger.kernel.org; linux-stm32@st-md-mailman.stormreply.com; linux-
> arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Looi, Hong =
Aun
> <hong.aun.looi@intel.com>; Voon, Weifeng <weifeng.voon@intel.com>; Song,
> Yoong Siang <yoong.siang.song@intel.com>; Choong, Yong Liang
> <yong.liang.choong@intel.com>
> Subject: Re: [PATCH net v3 1/1] net: phylink: Add module_exit()
>=20
> On Thu, Jan 04, 2024 at 06:12:55PM +0800, Gan, Yi Fang wrote:
> 65;7401;1c> In delete_module(), if mod->init callback is defined but mod-=
>exit
> callback
> > is not defined, it will assume the module cannot be removed and return
> > EBUSY. The module_exit() is missing from current phylink module drive
> > causing failure while unloading it.
>=20
> This is still missing the explanation why this is safe.
>=20
>=20
>     Andrew
>=20
> ---
> pw-bot: cr

Hi Andrew,

Regarding the justification on why it is safe to remove phylink,=20
we had done some memory leak check when unloading the phylink module.
=20
root@localhost:~# lsmod | grep "phylink"
phylink               73728  0
root@localhost:~# rmmod phylink
root@localhost:~# echo scan > /sys/kernel/debug/kmemleak
root@localhost:~# cat /sys/kernel/debug/kmemleak
root@localhost:~#
=20
So far, we didn't observe any memory leaking happened when unloading
phylink module. Is it sufficient or do you have any other suggestions to ch=
eck=20
on whether the module is safe to remove?

Best Regards,
Gan Yi Fang