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Date: Mon, 29 Jun 2026 18:19:55 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Shuhao Tan <tanshuhao@google.com>
Cc: "David S . Miller" <davem@davemloft.net>, Eric Dumazet
 <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>, Simon Horman
 <horms@kernel.org>, Andrew Lunn <andrew+netdev@lunn.ch>, Shuah Khan
 <shuah@kernel.org>, Mina Almasry <almasrymina@google.com>, Samiullah
 Khawaja <skhawaja@google.com>, Kuniyuki Iwashima <kuniyu@google.com>,
 netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-kselftest@vger.kernel.org
Subject: Re: [PATCH net-next v1 0/2] Reuse threaded NAPI kthread across
 napi_del()/napi_add().
Message-ID: <20260629181955.00e63b61@kernel.org>
In-Reply-To: <CAABY+HEcNnh+ATyA_JMg4LnVpP=egprTTi4UXxV9CfW2+71z+g@mail.gmail.com>
References: <20260629192029.4013794-1-tanshuhao@google.com>
	<20260629162619.55297244@kernel.org>
	<CAABY+HEcNnh+ATyA_JMg4LnVpP=egprTTi4UXxV9CfW2+71z+g@mail.gmail.com>
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On Mon, 29 Jun 2026 17:47:03 -0700 Shuhao Tan wrote:
> > Send a netdev Netlink notification when NAPI is re-created and
> > let the userspace re-apply the settings?  
> 
> It feels surprising that the userspace needs to reconfigure thread
> properties when changing NIC configurations unrelated to threading.
> Another downside is that when userspace configures NIC configurations
> in quick succession, re-application becomes messy because a previous
> re-application might still be in progress when the thread is gone.

Can you explain more about your deployment and system configuration
flow? We may be adding micro optimizations when the problem is that
we recreate the NAPIs in the first place.