From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH net-next-2.6] pkt_sched: gen_estimator: kill est_lock
 rwlock
Date: Mon, 07 Jun 2010 17:30:38 +0200
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Cc: David Miller <davem@davemloft.net>,
	netdev <netdev@vger.kernel.org>,
	Stephen Hemminger <shemminger@vyatta.com>,
	Jarek Poplawski <jarkao2@gmail.com>
To: Changli Gao <xiaosuo@gmail.com>
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Le lundi 07 juin 2010 =C3=A0 22:53 +0800, Changli Gao a =C3=A9crit :

> Hmm. I don't think it is correct.
>=20
> Look at this code:
>=20
> void xt_rateest_put(struct xt_rateest *est)
> {
>         mutex_lock(&xt_rateest_mutex);
>         if (--est->refcnt =3D=3D 0) {
>                 hlist_del(&est->list);
>                 gen_kill_estimator(&est->bstats, &est->rstats);
>                 kfree(est);
>         }
>         mutex_unlock(&xt_rateest_mutex);
> }
>=20
> est will be released after gen_kill_estimator() returns. After est is
> freed, there may still be some other CPUs running in the branch:
>      if (bstats) {
>          ....
>      }
>=20

Oh well, I think I knew this from a previous attempt, but then I
forgot :)

I'll provide an updated patch, so that no other attempt is tried next
yer, thanks !