From: kuznet@ms2.inr.ac.ru
Message-Id: <200308281553.TAA22047@dub.inr.ac.ru>
Subject: Re: tasklet_kill will always hang for recursive tasklets on a UP
To: quade@hsnr.de (Juergen Quade)
Date: Thu, 28 Aug 2003 19:53:11 +0400 (MSD)
Cc: nagendra_tomar@adaptec.com, linux-kernel@vger.kernel.org,
       wa@almesberger.net
In-Reply-To: <20030828152934.GA7924@hsnr.de> from "Juergen Quade" at  =?ISO-8859-1?Q?=20=E1=D7=C7?= 28, 2003 05:29:34 
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 978
Lines: 27

Hello!

> Here we have it! In my opintion, the line
> 
> 	clear_bit(TASKLET_STATE_SCHED, &t->state);
> 
> is just a _BUG_. 

No, really. The sense of tasklet_kill() is that tasklet is under complete
control of caller upon exit from it. This clear_bit just makes some (only
marginally useful) reinitialization for the case the user will want
to reuse the struct. Essentially, after tasklet_unlock_wait() you can do
everything with the struct, it is not an alive object anymore.


> 2. we should find some means to make it usable for recursive tasklets.

I would not say it is easy. When tasklet is enqueued on another cpu you
have no way to stop it unless you are in process context, where you can
sit and wait for completion.

Alexey
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/