Re: [PATCH 1/5] um: port: Move an assignment for the variable "fd" in port_wait()

Path	csiph.com!news.redatomik.org!aioe.org!bofh.it!news.nic.it!robomod
From	Jeff Dike <jdike@addtoit.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/5] um: port: Move an assignment for the variable "fd" in port_wait()
Date	Thu, 19 Jan 2017 01:30:01 +0100
Message-ID	<t18M1-2Gh-9@gated-at.bofh.it> (permalink)
References	<t16qR-15L-15@gated-at.bofh.it> <t16qS-15L-27@gated-at.bofh.it>
X-Original-To	SF Markus Elfring <elfring@users.sourceforge.net>
MIME-Version	1.0
Content-Type	text/plain; charset=us-ascii
Content-Disposition	inline
User-Agent	Mutt/1.6.1 (2016-04-27)
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	36
Organization	linux.* mail to news gateway
X-Original-Cc	user-mode-linux-devel@lists.sourceforge.net, user-mode-linux-user@lists.sourceforge.net, Anton Ivanov <aivanov@kot-begemot.co.uk>, Dan Williams <dan.j.williams@intel.com>, Hannes Reinecke <hare@suse.com>, Jens Axboe <axboe@fb.com>, Richard Weinberger <richard@nod.at>, LKML <linux-kernel@vger.kernel.org>, kernel-janitors@vger.kernel.org
X-Original-Date	Wed, 18 Jan 2017 19:03:30 -0500
X-Original-Message-ID	<20170119000330.GA12052@parts.user-mode-linux.org>
X-Original-References	<c10b7f33-f573-aa9f-239e-ccca5540f264@users.sourceforge.net> <4940ae24-c7ae-66ce-4c2a-5283607a5549@users.sourceforge.net>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1562328

Show key headers only | View raw

On Wed, Jan 18, 2017 at 10:56:17PM +0100, SF Markus Elfring wrote:
> diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
> index 40ca5cc275e9..b2bbda21c5f3 100644
> --- a/arch/um/drivers/port_kern.c
> +++ b/arch/um/drivers/port_kern.c
> @@ -230,10 +230,10 @@ int port_wait(void *data)
>  
>  	atomic_inc(&port->wait_count);
>  	while (1) {
> -		fd = -ERESTARTSYS;
> -		if (wait_for_completion_interruptible(&port->done))
> +		if (wait_for_completion_interruptible(&port->done)) {
> +			fd = -ERESTARTSYS;
>  			goto out;
> -
> +		}
>  		spin_lock(&port->lock);
>  
>  		conn = list_entry(port->connections.next, struct connection,
> -- 
> 2.11.0
>

The current code is pretty standard kernel coding style.  The inline
    fd = -ERESTARTSYS;
is likely free, or close to it, and I believe that having anything
besides a goto inside the if could make it significantly more
expensive.

				Jeff

-- 
Jeff Dike
AddToIt
978-254-0789 (o)
978-394-8986 (c)

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH 1/5] um: port: Move an assignment for the variable "fd" in  port_wait() SF Markus Elfring <elfring@users.sourceforge.net> - 2017-01-18 23:00 +0100
  Re: [PATCH 1/5] um: port: Move an assignment for the variable "fd"  in port_wait() Jeff Dike <jdike@addtoit.com> - 2017-01-19 01:30 +0100

csiph-web