From: kuznet@ms2.inr.ac.ru
Message-Id: <200012071721.UAA30863@ms2.inr.ac.ru>
Subject: Re: [Fwd: lost need_resched flag re-introduced?]
To: jsun@mvista.COM (Jun Sun)
Date: Thu, 7 Dec 2000 20:21:16 +0300 (MSK)
Cc: linux-kernel@vger.kernel.org
In-Reply-To: <3A2EE42C.F59317E9@mvista.com> from "Jun Sun" at Dec 7, 0 04:15:03 am
MIME-Version: 1.0
Sender: linux-kernel-owner@vger.kernel.org

Hello!

> > A while back I reported the lost need_resched flag bug ( it happens if
> > need_resched is set right before switch_to() is called).  Later on a one-line
> > fix is added to __schedule_tail().
> > 
> >         current->need_resched |= prev->need_resched;
> > 
> > I looked at the latest kernel and found this one is gone.  Is the lost
> > need_resched problem taken care of in some other way?  Or is it re-introduced?

It is removed not only because it was wrong (which you have found too),
but because it was useless even if copied correctly.

current->need_resched is not changed in interrupt context outside
runqueue lock except for scheduler timer, where copying results
in nothing but spurious reschedule.

Alexey
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