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From: Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Muhammad Falak R Wani
	<falakreyaz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Mike Marciniszyn
	<infinipath-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	Sean Hefty <sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
	Hal Rosenstock
	<hal.rosenstock-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	devel-gWbeCf7V1WCQmaza687I9mD2FQJk+8+b@public.gmane.org
Subject: Re: [PATCH] staging/rdma/hfi1: use RCU_INIT_POINTER() when NULLing.
Date: Mon, 2 May 2016 08:27:55 +0300	[thread overview]
Message-ID: <20160502052755.GC10276@leon.nu> (raw)
In-Reply-To: <1462106131-9073-1-git-send-email-falakreyaz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

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On Sun, May 01, 2016 at 06:05:31PM +0530, Muhammad Falak R Wani wrote:
> It is safe to use RCU_INIT_POINTER() to NULL a pointer, instead of
> rcu_assign_pointer().
> This results in slightly smaller/faster code.
> 
> Signed-off-by: Muhammad Falak R Wani <falakreyaz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

I'm fine with your commit message and don't need to resend, however
the statements like "smaller code" need to be supported by
./scripts/bloat-o-meter and "faster code" by performance analysis.

Reviewed-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

> ---
>  drivers/staging/rdma/hfi1/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rdma/hfi1/init.c b/drivers/staging/rdma/hfi1/init.c
> index cfcdc16..34e0f90 100644
> --- a/drivers/staging/rdma/hfi1/init.c
> +++ b/drivers/staging/rdma/hfi1/init.c
> @@ -1303,7 +1303,7 @@ static void cleanup_device_data(struct hfi1_devdata *dd)
>  
>  		spin_lock(&ppd->cc_state_lock);
>  		cc_state = get_cc_state(ppd);
> -		rcu_assign_pointer(ppd->cc_state, NULL);
> +		RCU_INIT_POINTER(ppd->cc_state, NULL);
>  		spin_unlock(&ppd->cc_state_lock);
>  
>  		if (cc_state)
> -- 
> 1.9.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

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WARNING: multiple messages have this Message-ID (diff)
From: Leon Romanovsky <leon@kernel.org>
To: Muhammad Falak R Wani <falakreyaz@gmail.com>
Cc: linux-kernel@vger.kernel.org,
	Mike Marciniszyn <infinipath@intel.com>,
	Doug Ledford <dledford@redhat.com>,
	Sean Hefty <sean.hefty@intel.com>,
	Hal Rosenstock <hal.rosenstock@gmail.com>,
	linux-rdma@vger.kernel.org, devel@driverdev.osuosl.org
Subject: Re: [PATCH] staging/rdma/hfi1: use RCU_INIT_POINTER() when NULLing.
Date: Mon, 2 May 2016 08:27:55 +0300	[thread overview]
Message-ID: <20160502052755.GC10276@leon.nu> (raw)
In-Reply-To: <1462106131-9073-1-git-send-email-falakreyaz@gmail.com>

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On Sun, May 01, 2016 at 06:05:31PM +0530, Muhammad Falak R Wani wrote:
> It is safe to use RCU_INIT_POINTER() to NULL a pointer, instead of
> rcu_assign_pointer().
> This results in slightly smaller/faster code.
> 
> Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>

I'm fine with your commit message and don't need to resend, however
the statements like "smaller code" need to be supported by
./scripts/bloat-o-meter and "faster code" by performance analysis.

Reviewed-by: Leon Romanovsky <leonro@mellanox.com>

> ---
>  drivers/staging/rdma/hfi1/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rdma/hfi1/init.c b/drivers/staging/rdma/hfi1/init.c
> index cfcdc16..34e0f90 100644
> --- a/drivers/staging/rdma/hfi1/init.c
> +++ b/drivers/staging/rdma/hfi1/init.c
> @@ -1303,7 +1303,7 @@ static void cleanup_device_data(struct hfi1_devdata *dd)
>  
>  		spin_lock(&ppd->cc_state_lock);
>  		cc_state = get_cc_state(ppd);
> -		rcu_assign_pointer(ppd->cc_state, NULL);
> +		RCU_INIT_POINTER(ppd->cc_state, NULL);
>  		spin_unlock(&ppd->cc_state_lock);
>  
>  		if (cc_state)
> -- 
> 1.9.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

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  parent reply	other threads:[~2016-05-02  5:27 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-01 12:35 [PATCH] staging/rdma/hfi1: use RCU_INIT_POINTER() when NULLing Muhammad Falak R Wani
2016-05-01 12:35 ` Muhammad Falak R Wani
     [not found] ` <1462106131-9073-1-git-send-email-falakreyaz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-05-02  5:27   ` Leon Romanovsky [this message]
2016-05-02  5:27     ` Leon Romanovsky
2016-05-13 19:38   ` Doug Ledford
2016-05-13 19:38     ` Doug Ledford

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