From: Greg KH <gregkh@linuxfoundation.org>
To: Dmitry Torokhov <dtor@vmware.com>
Cc: pv-drivers@vmware.com, linux-kernel@vger.kernel.org,
George Zhang <georgezhang@vmware.com>,
virtualization@lists.linux-foundation.org
Subject: Re: [Pv-drivers] [PATCH 05/12] VMCI: event handling implementation.
Date: Tue, 30 Oct 2012 08:50:12 -0700 [thread overview]
Message-ID: <20121030155012.GE14167@kroah.com> (raw)
In-Reply-To: <20121030045821.GD32055@dtor-ws.eng.vmware.com>
On Mon, Oct 29, 2012 at 09:58:21PM -0700, Dmitry Torokhov wrote:
> On Mon, Oct 29, 2012 at 07:24:46PM -0700, Greg KH wrote:
> > On Mon, Oct 29, 2012 at 06:04:27PM -0700, George Zhang wrote:
> > > +/*
> > > + * Releases the given VMCISubscription.
> > > + * Fires the destroy event if the reference count has gone to zero.
> > > + */
> > > +static void event_release(struct vmci_subscription *entry)
> > > +{
> > > + kref_put(&entry->kref, event_signal_destroy);
> > > +}
> >
> > Same question as before with the kref_put() call, what is handling the
> > locking here? It looks like a race to me.
>
> The reference is taken only if event is on the list (which managed by
> RCU and a mutex), so it is not possible to go from 0->1 for that
> refcount.
Ok, as long as you have audited this.
greg k-h
WARNING: multiple messages have this Message-ID (diff)
From: Greg KH <gregkh@linuxfoundation.org>
To: Dmitry Torokhov <dtor@vmware.com>
Cc: George Zhang <georgezhang@vmware.com>,
pv-drivers@vmware.com, linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [Pv-drivers] [PATCH 05/12] VMCI: event handling implementation.
Date: Tue, 30 Oct 2012 08:50:12 -0700 [thread overview]
Message-ID: <20121030155012.GE14167@kroah.com> (raw)
In-Reply-To: <20121030045821.GD32055@dtor-ws.eng.vmware.com>
On Mon, Oct 29, 2012 at 09:58:21PM -0700, Dmitry Torokhov wrote:
> On Mon, Oct 29, 2012 at 07:24:46PM -0700, Greg KH wrote:
> > On Mon, Oct 29, 2012 at 06:04:27PM -0700, George Zhang wrote:
> > > +/*
> > > + * Releases the given VMCISubscription.
> > > + * Fires the destroy event if the reference count has gone to zero.
> > > + */
> > > +static void event_release(struct vmci_subscription *entry)
> > > +{
> > > + kref_put(&entry->kref, event_signal_destroy);
> > > +}
> >
> > Same question as before with the kref_put() call, what is handling the
> > locking here? It looks like a race to me.
>
> The reference is taken only if event is on the list (which managed by
> RCU and a mutex), so it is not possible to go from 0->1 for that
> refcount.
Ok, as long as you have audited this.
greg k-h
next prev parent reply other threads:[~2012-10-30 15:50 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-30 1:03 [PATCH 00/12] VMCI for Linux upstreaming George Zhang
2012-10-30 1:03 ` [PATCH 01/12] VMCI: context implementation George Zhang
2012-10-30 2:07 ` Greg KH
2012-10-30 2:07 ` Greg KH
2012-10-30 2:10 ` Greg KH
2012-10-30 2:10 ` Greg KH
2012-10-30 4:01 ` [Pv-drivers] " Dmitry Torokhov
2012-10-30 4:01 ` Dmitry Torokhov
2012-10-30 15:46 ` Greg KH
2012-10-30 15:46 ` Greg KH
2012-10-30 15:56 ` Dmitry Torokhov
2012-10-30 15:56 ` Dmitry Torokhov
2012-10-30 1:03 ` [PATCH 02/12] VMCI: datagram implementation George Zhang
2012-10-30 1:04 ` [PATCH 03/12] VMCI: doorbell implementation George Zhang
2012-10-30 1:04 ` [PATCH 04/12] VMCI: device driver implementaton George Zhang
2012-10-30 2:21 ` Greg KH
2012-10-30 2:21 ` Greg KH
2012-10-30 2:23 ` Greg KH
2012-10-30 2:23 ` Greg KH
2012-10-30 4:15 ` [Pv-drivers] " Dmitry Torokhov
2012-10-30 4:15 ` Dmitry Torokhov
2012-10-30 15:49 ` Greg KH
2012-10-30 15:49 ` Greg KH
2012-10-30 1:04 ` [PATCH 05/12] VMCI: event handling implementation George Zhang
2012-10-30 2:24 ` Greg KH
2012-10-30 2:24 ` Greg KH
2012-10-30 4:58 ` [Pv-drivers] " Dmitry Torokhov
2012-10-30 4:58 ` Dmitry Torokhov
2012-10-30 15:50 ` Greg KH [this message]
2012-10-30 15:50 ` Greg KH
2012-10-30 2:26 ` Greg KH
2012-10-30 2:26 ` Greg KH
2012-10-30 5:01 ` [Pv-drivers] " Dmitry Torokhov
2012-10-30 5:01 ` Dmitry Torokhov
2012-10-30 15:50 ` Greg KH
2012-10-30 15:50 ` Greg KH
2012-10-30 15:59 ` Dmitry Torokhov
2012-10-30 15:59 ` Dmitry Torokhov
2012-10-30 1:04 ` [PATCH 06/12] VMCI: handle array implementation George Zhang
2012-10-30 1:04 ` [PATCH 07/12] VMCI: queue pairs implementation George Zhang
2012-10-30 1:04 ` [PATCH 08/12] VMCI: resource object implementation George Zhang
2012-10-30 1:04 ` George Zhang
2012-10-30 2:29 ` Greg KH
2012-10-30 2:29 ` Greg KH
2012-10-30 5:20 ` [Pv-drivers] " Dmitry Torokhov
2012-10-30 5:20 ` Dmitry Torokhov
2012-10-30 15:51 ` Greg KH
2012-10-30 15:51 ` Greg KH
2012-10-30 16:11 ` Dmitry Torokhov
2012-10-30 16:11 ` Dmitry Torokhov
2012-10-30 2:29 ` Greg KH
2012-10-30 2:29 ` Greg KH
2012-10-30 5:21 ` [Pv-drivers] " Dmitry Torokhov
2012-10-30 5:21 ` Dmitry Torokhov
2012-10-30 1:05 ` [PATCH 09/12] VMCI: routing implementation George Zhang
2012-10-30 1:05 ` George Zhang
2012-10-30 1:05 ` [PATCH 10/12] VMCI: guest side driver implementation George Zhang
2012-10-30 1:05 ` [PATCH 11/12] VMCI: host " George Zhang
2012-10-30 1:05 ` [PATCH 12/12] VMCI: Some header and config files George Zhang
2012-10-30 2:32 ` Greg KH
2012-10-30 2:32 ` Greg KH
2012-10-30 5:22 ` [Pv-drivers] " Dmitry Torokhov
2012-10-30 5:22 ` Dmitry Torokhov
2012-10-30 2:38 ` Greg KH
2012-10-30 2:38 ` Greg KH
2012-10-30 2:19 ` [PATCH 00/12] VMCI for Linux upstreaming Greg KH
2012-10-30 2:19 ` Greg KH
2012-10-30 4:07 ` [Pv-drivers] " Dmitry Torokhov
2012-10-30 4:07 ` Dmitry Torokhov
2012-10-30 15:48 ` Greg KH
2012-10-30 15:48 ` Greg KH
2012-10-30 16:18 ` Dmitry Torokhov
2012-10-30 16:18 ` Dmitry Torokhov
2012-10-30 16:27 ` Greg KH
2012-10-30 16:27 ` Greg KH
2012-10-30 19:43 ` Dmitry Torokhov
2012-10-30 19:43 ` Dmitry Torokhov
2012-10-30 19:59 ` Greg KH
2012-10-30 19:59 ` Greg KH
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