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Date:   Tue, 10 Jan 2023 16:30:43 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Eric Dumazet <edumazet@google.com>
Cc:     =?UTF-8?B?5p2O5ZOy?= <sensor1010@163.com>,
        Wei Wang <weiwan@google.com>, davem@davemloft.net,
        pabeni@redhat.com, bigeasy@linutronix.de, imagedong@tencent.com,
        kuniyu@amazon.com, petrm@nvidia.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1] net/dev.c : Remove redundant state settings after
 waking up
Message-ID: <20230110163043.069c9aa4@kernel.org>
In-Reply-To: <CANn89iL0EYuGASWaXPwKN+E6mZvFicbDKOoZVA8N+BXFQV7e2A@mail.gmail.com>
References: <20230110091409.2962-1-sensor1010@163.com>
        <CANn89iL0EYuGASWaXPwKN+E6mZvFicbDKOoZVA8N+BXFQV7e2A@mail.gmail.com>
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On Tue, 10 Jan 2023 10:29:20 +0100 Eric Dumazet wrote:
> > the task status has been set to TASK_RUNNING in shcedule(),
> > no need to set again here  
> 
> Changelog is rather confusing, this does not match the patch, which
> removes one set_current_state(TASK_INTERRUPTIBLE);
> 
> TASK_INTERRUPTIBLE != TASK_RUNNING
> 
> Patch itself looks okay (but has nothing to do with thread state after
> schedule()),
> you should have CC Wei Wang because she
> authored commit cb038357937e net: fix race between napi kthread mode
> and busy poll

AFAIU this is the semi-idiomatic way of handling wait loops.
It's not schedule() that may set the task state to TASK_RUNNING,
it's whoever wakes the process and makes the "wait condition" true.
In this case - test_bit(NAPI_STATE_SCHED, &napi->state)

I vote to not futz with this logic.