From: Jim Houston <jim.houston@comcast.net>
To: dipankar@in.ibm.com
Cc: paulmck@us.ibm.com, linux-kernel@vger.kernel.org
Subject: Re: [RFC&PATCH] Alternative RCU implementation
Date: 31 Aug 2004 20:10:50 -0400 [thread overview]
Message-ID: <1093997450.4069.1.camel@new.localdomain> (raw)
In-Reply-To: <20040830173853.GB4639@in.ibm.com>
On Mon, 2004-08-30 at 13:38, Dipankar Sarma wrote:
> > I'm also trying to figure out if I need the call_rcu_bh() changes.
> > Since my patch will recognize a grace periods as soon as any
> > pending read-side critical sections complete, I suspect that I
> > don't need this change.
>
> Except that under a softirq flood, a reader in a different read-side
> critical section may get delayed a lot holding up RCU. Let me know
> if I am missing something here.
Hi Dipankar,
O.k. That makes sense. So the rcu_read_lock_bh(), rcu_read_unlock_bh()
and call_rcu_bh() would be the preferred interface. Are there cases
where they can't be used? How do you decide where to use the _bh
flavor?
I see that local_bh_enable() WARNS if interrupts are disabled. Is that
the issue? Are rcu_read_lock()/rcu_read_unlock() ever called from
code which disables interrupts?
Jim Houston - Concurrent Computer Corp.
next prev parent reply other threads:[~2004-09-01 0:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <m3brgwgi30.fsf@new.localdomain>
2004-08-30 0:43 ` [RFC&PATCH] Alternative RCU implementation Paul E. McKenney
2004-08-30 17:13 ` Jim Houston
2004-08-30 17:38 ` Dipankar Sarma
2004-09-01 0:10 ` Jim Houston [this message]
2004-09-01 0:57 ` Paul E. McKenney
2004-08-30 18:52 ` Paul E. McKenney
2004-08-31 3:22 ` Jim Houston
2004-09-01 3:53 ` Paul E. McKenney
2004-09-01 13:02 ` Jim Houston
2004-09-02 16:38 ` Paul E. McKenney
2004-09-02 18:54 ` Jim Houston
2004-09-02 21:20 ` Manfred Spraul
2004-09-03 1:19 ` Jim Houston
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