From: Andi Kleen <andi@firstfloor.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org, tglx@linutronix.de,
Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 1/3] posix-timers: remove idr_lock
Date: Fri, 10 Jun 2011 22:44:28 +0200 [thread overview]
Message-ID: <20110610204428.GB10930@one.firstfloor.org> (raw)
In-Reply-To: <1307738438.2872.7.camel@edumazet-laptop>
On Fri, Jun 10, 2011 at 10:40:38PM +0200, Eric Dumazet wrote:
> Le vendredi 10 juin 2011 à 13:13 -0700, Andi Kleen a écrit :
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > idr_lock is only used to protect the global posix_timers idr,
> > but idr does its own locking (or RCUing) anyways and doesn't
> > need it. So remove it.
>
> Are you sure of this assertion Andi ?
>
> I believe we need an external synchronization before calling
> idr_remove() / idr_get_new()
idr has its own lock and from a quick check it seemed to always
take it when needed. Also ipc/* don't take a lock for this as far
as I can see, and I think RCU idr was designed for that.
-Andi
next prev parent reply other threads:[~2011-06-10 20:44 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-10 20:13 Andi Kleen
2011-06-10 20:13 ` [PATCH 2/3] posix-timers: move global timer id management to signal_struct Andi Kleen
2011-06-10 20:13 ` [PATCH 3/3] posix-timers: limit the number of posix timers per process Andi Kleen
2011-06-10 20:40 ` [PATCH 1/3] posix-timers: remove idr_lock Eric Dumazet
2011-06-10 20:44 ` Andi Kleen [this message]
2011-06-10 20:52 ` Eric Dumazet
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