linux-nfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
@ 2018-05-24 13:26 Waiman Long
  2018-06-19 23:09 ` Waiman Long
  2018-06-20  9:17 ` Peter Zijlstra
  0 siblings, 2 replies; 4+ messages in thread
From: Waiman Long @ 2018-05-24 13:26 UTC (permalink / raw)
  To: Ingo Molnar, Peter Zijlstra, Thomas Gleixner
  Cc: linux-kernel, Davidlohr Bueso, Dan Williams, Arnd Bergmann,
	linux-nfs, Waiman Long

It was found that the use of up_read_non_owner() in NFS was causing
the following warning when DEBUG_RWSEMS was configured.

  DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))

Looking into the rwsem.c file, it was discovered that the corresponding
down_read_non_owner() function was not setting the owner field properly.
This is fixed now, and the warning should be gone.

Signed-off-by: Waiman Long <longman@redhat.com>
---
 kernel/locking/rwsem.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index bc1e507..776308d 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem)
 	might_sleep();
 
 	__down_read(sem);
+	rwsem_set_reader_owned(sem);
 }
 
 EXPORT_SYMBOL(down_read_non_owner);
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
  2018-05-24 13:26 [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS Waiman Long
@ 2018-06-19 23:09 ` Waiman Long
  2018-06-20  5:49   ` [Customers.Eckelmann] " Schenk, Gavin
  2018-06-20  9:17 ` Peter Zijlstra
  1 sibling, 1 reply; 4+ messages in thread
From: Waiman Long @ 2018-06-19 23:09 UTC (permalink / raw)
  To: Ingo Molnar, Peter Zijlstra, Thomas Gleixner
  Cc: linux-kernel, Davidlohr Bueso, Dan Williams, Arnd Bergmann,
	linux-nfs, Uwe Kleine-König

On 05/24/2018 09:26 PM, Waiman Long wrote:
> It was found that the use of up_read_non_owner() in NFS was causing
> the following warning when DEBUG_RWSEMS was configured.
>
>   DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))
>
> Looking into the rwsem.c file, it was discovered that the corresponding
> down_read_non_owner() function was not setting the owner field properly.
> This is fixed now, and the warning should be gone.
>
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
>  kernel/locking/rwsem.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
> index bc1e507..776308d 100644
> --- a/kernel/locking/rwsem.c
> +++ b/kernel/locking/rwsem.c
> @@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem)
>  	might_sleep();
>  tch
>  	__down_read(sem);
> +	rwsem_set_reader_owned(sem);
>  }
>  
>  EXPORT_SYMBOL(down_read_non_owner);

Since the 4.18 merge window has been closed. Can that patch be merged
upstream?

Cheers,
Longman


^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [Customers.Eckelmann] [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
  2018-06-19 23:09 ` Waiman Long
@ 2018-06-20  5:49   ` Schenk, Gavin
  0 siblings, 0 replies; 4+ messages in thread
From: Schenk, Gavin @ 2018-06-20  5:49 UTC (permalink / raw)
  To: tglx, longman, peterz, mingo
  Cc: dan.j.williams, linux-kernel, u.kleine-koenig, linux-nfs, arnd, dave
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^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
  2018-05-24 13:26 [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS Waiman Long
  2018-06-19 23:09 ` Waiman Long
@ 2018-06-20  9:17 ` Peter Zijlstra
  1 sibling, 0 replies; 4+ messages in thread
From: Peter Zijlstra @ 2018-06-20  9:17 UTC (permalink / raw)
  To: Waiman Long
  Cc: Ingo Molnar, Thomas Gleixner, linux-kernel, Davidlohr Bueso,
	Dan Williams, Arnd Bergmann, linux-nfs

On Thu, May 24, 2018 at 09:26:38AM -0400, Waiman Long wrote:
> It was found that the use of up_read_non_owner() in NFS was causing
> the following warning when DEBUG_RWSEMS was configured.
> 
>   DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))
> 
> Looking into the rwsem.c file, it was discovered that the corresponding
> down_read_non_owner() function was not setting the owner field properly.
> This is fixed now, and the warning should be gone.
> 
> Signed-off-by: Waiman Long <longman@redhat.com>

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

> ---
>  kernel/locking/rwsem.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
> index bc1e507..776308d 100644
> --- a/kernel/locking/rwsem.c
> +++ b/kernel/locking/rwsem.c
> @@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem)
>  	might_sleep();
>  
>  	__down_read(sem);
> +	rwsem_set_reader_owned(sem);
>  }
>  
>  EXPORT_SYMBOL(down_read_non_owner);
> -- 
> 1.8.3.1
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-06-20  9:17 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-05-24 13:26 [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS Waiman Long
2018-06-19 23:09 ` Waiman Long
2018-06-20  5:49   ` [Customers.Eckelmann] " Schenk, Gavin
2018-06-20  9:17 ` Peter Zijlstra

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).