Re: [PATCH] net: Disambiguate kernel message

[Joe Perches <joe@perches.com>]

On Tue, 2012-01-31 at 10:15 -0800, Arun Sharma wrote:
> On Mon, Jan 30, 2012 at 08:22:03PM -0800, Bjorn Helgaas wrote:
> > > We print a different message depending on whether we're out
> > > of TCP memory or there are too many orphan sockets.
> > 
> > This patch mentions pairs of messages that are almost the same, but
> > not quite.  If they're supposed to be different, I'd suggest making
> > them clearly different.  As it is, the differences look like careless
> > mistakes:
> 
> Good point. Updated patch changes the existing printks to be
> the same as well.
[]
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
[]
> @@ -2014,11 +2014,24 @@ adjudge_to_death:
[]
> +		if (too_many_orphans) {
>  			if (net_ratelimit())
> -				printk(KERN_INFO "TCP: too many of orphaned "
> +				printk(KERN_INFO "TCP: too many orphaned "
>  				       "sockets\n");
> +		}
> +
> +		if (out_of_socket_memory) {
> +			if (net_ratelimit())
> +				printk(KERN_INFO "TCP: out of memory. "
> +				       "Consider tuning tcp_mem\n");
> +		}
> +
[]
> diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
[]
> @@ -77,9 +78,14 @@ static int tcp_out_of_resources(struct sock *sk, int do_reset)
[]
> +	too_many_orphans = tcp_too_many_orphans(sk, shift);
> +	out_of_socket_memory = tcp_out_of_memory(sk);
> +	if (too_many_orphans || out_of_socket_memory) {
> +		if (out_of_socket_memory && net_ratelimit())
> +			printk(KERN_INFO "TCP: out of memory. "
> +					 "Consider tuning tcp_mem\n");
> +		if (too_many_orphans && net_ratelimit())
> +			printk(KERN_INFO "TCP: too many orphaned sockets\n");

These 2 blocks emit the messages in different order.

It might be useful to use a generic routine.

void tcp_log_oom(bool orphans, bool socket_memory)
{
	if (!net_ratelimit())
		return;
	if (orphans)
		pr_info("too many orphaned sockets\n");
	if (socket_memory)
		pr_info("out of socket memory - consider tuning tcp_mem\n");
}