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

Zhang Yanfei
2013-02-07T08:41:32Z

于 2013年02月07日 16:40, Julian Anastasov 写道:
>
> 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@linux-foundation.org>
>> Cc: David Miller <davem@davemloft.net>
>> Cc: Julian Anastasov <ja@ssi.bg>
>> Cc: Simon Horman <horms@verge.net.au>
>> Signed-off-by: Zhang Yanfei <zhangyanfei@cn.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.
>

I see. Thanks for your review and your explanation!

Zhang