Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 1 Apr 2020 11:39:04 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     liyueyi <liyueyi@live.com>
Cc:     gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
        liyueyi <liyueyi@xiaomi.com>
Subject: Re: [PATCH] kthread: set kthread state to TASK_IDLE.
Message-ID: <20200401093904.GX20713@hirez.programming.kicks-ass.net>
References: <DM6PR11MB3531D3B164357B2DC476102DDFC90@DM6PR11MB3531.namprd11.prod.outlook.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <DM6PR11MB3531D3B164357B2DC476102DDFC90@DM6PR11MB3531.namprd11.prod.outlook.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Apr 01, 2020 at 02:52:15PM +0800, liyueyi wrote:
> From: liyueyi <liyueyi@xiaomi.com>
> 
> Currently kthread() sleeps in TASK_UNINTERRUPTIBLE state waiting
> for the first wakeup, it may be detected by DETECT_HUNG_TASK if
> the first wakeup is coming later. Since kernel has introduced
> TASK_IDLE, change kthread state to TASK_IDLE.

How the heck can that ever happen anyway? Is this some virt
brain-damage?

And how is it not a real problem when it takes this long?