linux-kernel - Re: [ofa-general] Re: [PATCH 10/14] infiniband: use printk_once

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Message-Id: <200908100936.26963.jackm@dev.mellanox.co.il>
Date:	Mon, 10 Aug 2009 09:36:26 +0300
From:	Jack Morgenstein <jackm@....mellanox.co.il>
To:	general@...ts.openfabrics.org
Cc:	Roland Dreier <rdreier@...co.com>,
	Marcin Slusarz <marcin.slusarz@...il.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [ofa-general] Re: [PATCH 10/14] infiniband: use printk_once

I'm a bit nervous about this one.  
printk_once will print once ONLY if CONFIG_PRINTK is set in include/linux/autoconf.h
(i.e., when the kernel is configured).  Otherwise, it gets defined to printk --
and it will always print in this case.
(see 2.6.30.xx kernel include file "include/linux/kernel.h", lines 235, 249, and 272).

Do you think that distributions will ALWAYS have CONFIG_PRINTK defined?

I would prefer to wait until printk_once printing only once is not config-dependent.

-Jack

On Monday 10 August 2009 08:00, Roland Dreier wrote:
> 
>  >  drivers/infiniband/hw/cxgb3/iwch.c |    4 +---
>  >  drivers/infiniband/hw/mlx4/main.c  |    6 +-----
> 
>  > --- a/drivers/infiniband/hw/mlx4/main.c
>  > +++ b/drivers/infiniband/hw/mlx4/main.c
>  > @@ -540,15 +540,11 @@ static struct device_attribute *mlx4_class_attributes[] = {
>  >  
>  >  static void *mlx4_ib_add(struct mlx4_dev *dev)
>  >  {
>  > -	static int mlx4_ib_version_printed;
>  >  	struct mlx4_ib_dev *ibdev;
>  >  	int num_ports = 0;
>  >  	int i;
>  >  
>  > -	if (!mlx4_ib_version_printed) {
>  > -		printk(KERN_INFO "%s", mlx4_ib_version);
>  > -		++mlx4_ib_version_printed;
>  > -	}
>  > +	printk_once(KERN_INFO "%s", mlx4_ib_version);
>  >  
>  >  	mlx4_foreach_port(i, dev, MLX4_PORT_TYPE_IB)
>  >  		num_ports++;
> 
> Looks fine but there is near-identical code in
> drivers/infiniband/hw/mthca/mthca_main.c that you might as well convert
> too.
> 
> Thanks,
>   Roland
> _______________________________________________
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> 
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> 
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