netdev - Re: [PATCH v2 net-next 0/4] net: reduce RTNL pressure in unregister

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CANn89iLPNdGsFUFdeJh3d-4P3bcOSoddz1L-L54+8WKsriMReA@mail.gmail.com>
Date: Wed, 8 Jan 2025 17:54:33 +0100
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, 
	Paolo Abeni <pabeni@...hat.com>
Cc: netdev@...r.kernel.org, Simon Horman <horms@...nel.org>, eric.dumazet@...il.com
Subject: Re: [PATCH v2 net-next 0/4] net: reduce RTNL pressure in unregister_netdevice()

On Wed, Jan 8, 2025 at 5:22 PM Eric Dumazet <edumazet@...gle.com> wrote:
>
> One major source of RTNL contention resides in unregister_netdevice()
>
> Due to RCU protection of various network structures, and
> unregister_netdevice() being a synchronous function,
> it is calling potentially slow functions while holding RTNL.
>
> I think we can release RTNL in two points, so that three
> slow functions are called while RTNL can be used
> by other threads.
>
> v2: Only temporarily release RTNL from cleanup_net()
> v1: https://lore.kernel.org/netdev/20250107130906.098fc8d6@kernel.org/T/#m398c95f5778e1ff70938e079d3c4c43c050ad2a6

Hmmm. more work is needed, because __rtnl_unlock() might see a

 WARN_ON(!list_empty(&net_todo_list));

I will send a v3 later.