linux-kernel - Re: [PATCH v2] net: fix functions and variables related to netns_ipvs->sysctl_sync_qlen

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 7 Feb 2013 10:40:26 +0200 (EET)
From:	Julian Anastasov <ja@....bg>
To:	Zhang Yanfei <zhangyanfei@...fujitsu.com>
cc:	Andrew Morton <akpm@...ux-foundation.org>, davem@...emloft.net,
	Simon Horman <horms@...ge.net.au>,
	Linux MM <linux-mm@...ck.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] net: fix functions and variables related to
 netns_ipvs->sysctl_sync_qlen_max


	Hello,

On Thu, 7 Feb 2013, Zhang Yanfei wrote:

> Since the type of netns_ipvs->sysctl_sync_qlen_max has been changed to
> unsigned long, type of its related proc var sync_qlen_max should be changed
> to unsigned long, too. Also the return type of function sysctl_sync_qlen_max().
> 
> Besides, the type of ipvs_master_sync_state->sync_queue_len should also be
> changed to unsigned long.

	v2 looks fine. Thanks! Regarding your question
see below...

> Changelog from V1:
> - change type of ipvs_master_sync_state->sync_queue_len to unsigned long
>   as Simon addressed.
> 
> Cc: Andrew Morton <akpm@...ux-foundation.org>
> Cc: David Miller <davem@...emloft.net>
> Cc: Julian Anastasov <ja@....bg>
> Cc: Simon Horman <horms@...ge.net.au>
> Signed-off-by: Zhang Yanfei <zhangyanfei@...fujitsu.com>
> ---
>  include/net/ip_vs.h            |    6 +++---
>  net/netfilter/ipvs/ip_vs_ctl.c |    4 ++--
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
> index 68c69d5..1d56f92 100644
> --- a/include/net/ip_vs.h
> +++ b/include/net/ip_vs.h
> @@ -874,7 +874,7 @@ struct ip_vs_app {
>  struct ipvs_master_sync_state {
>  	struct list_head	sync_queue;
>  	struct ip_vs_sync_buff	*sync_buff;
> -	int			sync_queue_len;
> +	unsigned long		sync_queue_len;
>  	unsigned int		sync_queue_delay;
>  	struct task_struct	*master_thread;
>  	struct delayed_work	master_wakeup_work;
> @@ -1052,7 +1052,7 @@ static inline int sysctl_sync_ports(struct netns_ipvs *ipvs)
>  	return ACCESS_ONCE(ipvs->sysctl_sync_ports);
>  }
>  
> -static inline int sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
> +static inline unsigned long sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
>  {
>  	return ipvs->sysctl_sync_qlen_max;
>  }
> @@ -1099,7 +1099,7 @@ static inline int sysctl_sync_ports(struct netns_ipvs *ipvs)
>  	return 1;
>  }
>  
> -static inline int sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
> +static inline unsigned long sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
>  {
>  	return IPVS_SYNC_QLEN_MAX;
>  }
> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> index ec664cb..d79a530 100644
> --- a/net/netfilter/ipvs/ip_vs_ctl.c
> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> @@ -1747,9 +1747,9 @@ static struct ctl_table vs_vars[] = {
>  	},
>  	{
>  		.procname	= "sync_qlen_max",
> -		.maxlen		= sizeof(int),
> +		.maxlen		= sizeof(unsigned long),
>  		.mode		= 0644,
> -		.proc_handler	= proc_dointvec,
> +		.proc_handler	= proc_doulongvec_minmax,
>  	},
>  	{
>  		.procname	= "sync_sock_size",
> -- 
> 1.7.1


> Another question about the sysctl_sync_qlen_max:
> This variable is assigned as:
> 
> ipvs->sysctl_sync_qlen_max = nr_free_buffer_pages() / 32;
> 
> The function nr_free_buffer_pages actually means: counts of pages
> which are beyond high watermark within ZONE_DMA and ZONE_NORMAL.
> 
> is it ok to be called here? Some people misused this function because
> the function name was misleading them. I am sorry I am totally not
> familiar with the ipvs code, so I am just asking you about
> this.

	Using nr_free_buffer_pages should be fine here.
We are using it as rough estimation for the number of sync
buffers we can use in NORMAL zones. We are using dev->mtu
for such buffers, so it can take a PAGE_SIZE for a buffer.
We are not interested in HIGHMEM size. high watermarks
should have negliable effect. I'm even not sure whether
we need to clamp it for systems with TBs of memory.

Regards

--
Julian Anastasov <ja@....bg>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/