Date: Thu, 27 Oct 2016 17:15:21 -0400 (EDT)
Message-Id: <20161027.171521.641636732714679018.davem@davemloft.net>
To: avagin@openvz.org
Cc: ebiederm@xmission.com, containers@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        xiyou.wangcong@gmail.com
Subject: Re: [PATCH v2] net: skip genenerating uevents for network
 namespaces that are exiting
From: David Miller <davem@davemloft.net>
In-Reply-To: <1477361393-24876-1-git-send-email-avagin@openvz.org>
References: <1477361393-24876-1-git-send-email-avagin@openvz.org>
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From: Andrei Vagin <avagin@openvz.org>
Date: Mon, 24 Oct 2016 19:09:53 -0700

> No one can see these events, because a network namespace can not be
> destroyed, if it has sockets.
> 
> Unlike other devices, uevent-s for network devices are generated
> only inside their network namespaces. They are filtered in
> kobj_bcast_filter()
> 
> My experiments shows that net namespaces are destroyed more 30% faster
> with this optimization.
> 
> Here is a perf output for destroying network namespaces without this
> patch.
 ...
> It's very critical to optimize the exit path for network namespaces,
> because they are destroyed under net_mutex and many namespaces can be
> destroyed for one iteration.
> 
> v2: use dev_set_uevent_suppress()
> 
> Cc: Cong Wang <xiyou.wangcong@gmail.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric W. Biederman <ebiederm@xmission.com>
> Signed-off-by: Andrei Vagin <avagin@openvz.org>

Applied to net-next, thanks.