netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH net-next-2.6] net: introduce rcu_dereference_read_lock_or_rtnl
@ 2010-09-07 20:11 Eric Dumazet
  2010-09-07 20:49 ` Jarek Poplawski
  0 siblings, 1 reply; 6+ messages in thread
From: Eric Dumazet @ 2010-09-07 20:11 UTC (permalink / raw)
  To: David Miller; +Cc: netdev

We use rcu_dereference_check(p, rcu_read_lock_held() ||
lockdep_rtnl_is_held()) several times in network stack.

More usages to come too, so its time to create a helper.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
include/linux/rtnetlink.h |   12 ++++++++++++

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 58d4449..5ba48bb 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -745,10 +745,22 @@ extern void rtnl_lock(void);
 extern void rtnl_unlock(void);
 extern int rtnl_trylock(void);
 extern int rtnl_is_locked(void);
+
 #ifdef CONFIG_PROVE_LOCKING
 extern int lockdep_rtnl_is_held(void);
 #endif /* #ifdef CONFIG_PROVE_LOCKING */
 
+/**
+ * rcu_dereference_read_lock_or_rtnl - rcu_dereference with debug checking
+ * @p: The pointer to read, prior to dereferencing
+ *
+ * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
+ * or RTNL
+ */
+#define rcu_dereference_read_lock_or_rtnl(p)				\
+		rcu_dereference_check(p, rcu_read_lock_held() ||	\
+					 lockdep_rtnl_is_held());
+
 extern void rtnetlink_init(void);
 extern void __rtnl_unlock(void);
 



^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH net-next-2.6] net: introduce rcu_dereference_read_lock_or_rtnl
  2010-09-07 20:11 [PATCH net-next-2.6] net: introduce rcu_dereference_read_lock_or_rtnl Eric Dumazet
@ 2010-09-07 20:49 ` Jarek Poplawski
  2010-09-07 21:07   ` [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl Eric Dumazet
  0 siblings, 1 reply; 6+ messages in thread
From: Jarek Poplawski @ 2010-09-07 20:49 UTC (permalink / raw)
  To: Eric Dumazet; +Cc: David Miller, netdev

Eric Dumazet wrote, On 09/07/2010 10:11 PM:

> We use rcu_dereference_check(p, rcu_read_lock_held() ||
> lockdep_rtnl_is_held()) several times in network stack.
> 
> More usages to come too, so its time to create a helper.
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> ---
> include/linux/rtnetlink.h |   12 ++++++++++++
> 
> diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
> index 58d4449..5ba48bb 100644
> --- a/include/linux/rtnetlink.h
> +++ b/include/linux/rtnetlink.h
> @@ -745,10 +745,22 @@ extern void rtnl_lock(void);
>  extern void rtnl_unlock(void);
>  extern int rtnl_trylock(void);
>  extern int rtnl_is_locked(void);
> +
>  #ifdef CONFIG_PROVE_LOCKING
>  extern int lockdep_rtnl_is_held(void);
>  #endif /* #ifdef CONFIG_PROVE_LOCKING */
>  
> +/**
> + * rcu_dereference_read_lock_or_rtnl - rcu_dereference with debug checking
> + * @p: The pointer to read, prior to dereferencing
> + *
> + * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
> + * or RTNL
> + */
> +#define rcu_dereference_read_lock_or_rtnl(p)


My proposal is to shorten the name, and since rcu_read_lock
part seems obvious, maybe rcu_dereference_rtnl() only?

Jarek P.

				\
> +		rcu_dereference_check(p, rcu_read_lock_held() ||	\
> +					 lockdep_rtnl_is_held());
> +
>  extern void rtnetlink_init(void);
>  extern void __rtnl_unlock(void);
>  
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 



^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl
  2010-09-07 20:49 ` Jarek Poplawski
@ 2010-09-07 21:07   ` Eric Dumazet
  2010-09-08 18:29     ` Ben Hutchings
  0 siblings, 1 reply; 6+ messages in thread
From: Eric Dumazet @ 2010-09-07 21:07 UTC (permalink / raw)
  To: Jarek Poplawski; +Cc: David Miller, netdev

Le mardi 07 septembre 2010 à 22:49 +0200, Jarek Poplawski a écrit :
> Eric Dumazet wrote, On 09/07/2010 10:11 PM:
> 
> > We use rcu_dereference_check(p, rcu_read_lock_held() ||
> > lockdep_rtnl_is_held()) several times in network stack.
> > 
> > More usages to come too, so its time to create a helper.
> > 
> > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> > ---
> > include/linux/rtnetlink.h |   12 ++++++++++++
> > 
> > diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
> > index 58d4449..5ba48bb 100644
> > --- a/include/linux/rtnetlink.h
> > +++ b/include/linux/rtnetlink.h
> > @@ -745,10 +745,22 @@ extern void rtnl_lock(void);
> >  extern void rtnl_unlock(void);
> >  extern int rtnl_trylock(void);
> >  extern int rtnl_is_locked(void);
> > +
> >  #ifdef CONFIG_PROVE_LOCKING
> >  extern int lockdep_rtnl_is_held(void);
> >  #endif /* #ifdef CONFIG_PROVE_LOCKING */
> >  
> > +/**
> > + * rcu_dereference_read_lock_or_rtnl - rcu_dereference with debug checking
> > + * @p: The pointer to read, prior to dereferencing
> > + *
> > + * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
> > + * or RTNL
> > + */
> > +#define rcu_dereference_read_lock_or_rtnl(p)
> 
> 
> My proposal is to shorten the name, and since rcu_read_lock
> part seems obvious, maybe rcu_dereference_rtnl() only?

Yes, name is absolutely awful, I am very bad at this kind of games :)

Thanks !

[PATCH net-next-2.6] net: introduce rcu_dereference_rtnl

We use rcu_dereference_check(p, rcu_read_lock_held() ||
lockdep_rtnl_is_held()) several times in network stack.

More usages to come too, so its time to create a helper.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
 include/linux/rtnetlink.h |   11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 58d4449..057a08f 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -749,6 +749,17 @@ extern int rtnl_is_locked(void);
 extern int lockdep_rtnl_is_held(void);
 #endif /* #ifdef CONFIG_PROVE_LOCKING */
 
+/**
+ * rcu_dereference_rtnl - rcu_dereference with debug checking
+ * @p: The pointer to read, prior to dereferencing
+ *
+ * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
+ * or RTNL
+ */
+#define rcu_dereference_rtnl(p)					\
+	rcu_dereference_check(p, rcu_read_lock_held() ||	\
+				 lockdep_rtnl_is_held());
+
 extern void rtnetlink_init(void);
 extern void __rtnl_unlock(void);
 



^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl
  2010-09-07 21:07   ` [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl Eric Dumazet
@ 2010-09-08 18:29     ` Ben Hutchings
  2010-09-08 18:44       ` Eric Dumazet
  0 siblings, 1 reply; 6+ messages in thread
From: Ben Hutchings @ 2010-09-08 18:29 UTC (permalink / raw)
  To: Eric Dumazet; +Cc: Jarek Poplawski, David Miller, netdev

On Tue, 2010-09-07 at 23:07 +0200, Eric Dumazet wrote:
[...]
> +/**
> + * rcu_dereference_rtnl - rcu_dereference with debug checking
> + * @p: The pointer to read, prior to dereferencing
> + *
> + * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
> + * or RTNL
> + */
> +#define rcu_dereference_rtnl(p)					\
> +	rcu_dereference_check(p, rcu_read_lock_held() ||	\
> +				 lockdep_rtnl_is_held());
[...]

No semicolon on the end, please.  The 'caller' will add that.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.



^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl
  2010-09-08 18:29     ` Ben Hutchings
@ 2010-09-08 18:44       ` Eric Dumazet
  2010-09-08 21:15         ` David Miller
  0 siblings, 1 reply; 6+ messages in thread
From: Eric Dumazet @ 2010-09-08 18:44 UTC (permalink / raw)
  To: Ben Hutchings; +Cc: Jarek Poplawski, David Miller, netdev

Le mercredi 08 septembre 2010 à 19:29 +0100, Ben Hutchings a écrit :

> No semicolon on the end, please.  The 'caller' will add that.

Oh definitely, thanks !

[PATCH net-next-2.6] net: introduce rcu_dereference_rtnl

We use rcu_dereference_check(p, rcu_read_lock_held() ||
lockdep_rtnl_is_held()) several times in network stack.

More usages to come too, so its time to create a helper.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
 include/linux/rtnetlink.h |   11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 58d4449..263690d 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -749,6 +749,17 @@ extern int rtnl_is_locked(void);
 extern int lockdep_rtnl_is_held(void);
 #endif /* #ifdef CONFIG_PROVE_LOCKING */
 
+/**
+ * rcu_dereference_rtnl - rcu_dereference with debug checking
+ * @p: The pointer to read, prior to dereferencing
+ *
+ * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
+ * or RTNL
+ */
+#define rcu_dereference_rtnl(p)					\
+	rcu_dereference_check(p, rcu_read_lock_held() ||	\
+				 lockdep_rtnl_is_held())
+
 extern void rtnetlink_init(void);
 extern void __rtnl_unlock(void);
 



^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl
  2010-09-08 18:44       ` Eric Dumazet
@ 2010-09-08 21:15         ` David Miller
  0 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2010-09-08 21:15 UTC (permalink / raw)
  To: eric.dumazet; +Cc: bhutchings, jarkao2, netdev

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 08 Sep 2010 20:44:29 +0200

> Le mercredi 08 septembre 2010 à 19:29 +0100, Ben Hutchings a écrit :
> 
>> No semicolon on the end, please.  The 'caller' will add that.
> 
> Oh definitely, thanks !
> 
> [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl
> 
> We use rcu_dereference_check(p, rcu_read_lock_held() ||
> lockdep_rtnl_is_held()) several times in network stack.
> 
> More usages to come too, so its time to create a helper.
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>

Applied, thanks Eric.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2010-09-08 21:15 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-09-07 20:11 [PATCH net-next-2.6] net: introduce rcu_dereference_read_lock_or_rtnl Eric Dumazet
2010-09-07 20:49 ` Jarek Poplawski
2010-09-07 21:07   ` [PATCH net-next-2.6] net: introduce rcu_dereference_rtnl Eric Dumazet
2010-09-08 18:29     ` Ben Hutchings
2010-09-08 18:44       ` Eric Dumazet
2010-09-08 21:15         ` David Miller

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).