Subject: Re: [PATCH 2/2] ss: implement -M option to get all memory information

From: Pavel Emelyanov <[email-masked]>
Date: Thu, 03 May 2012 12:37:10 +0400

On 05/02/2012 11:00 PM, Stephen Hemminger wrote:
> On Wed, 02 May 2012 17:45:02 +0800
> Shan Wei <[email-masked]> wrote:
> 
>> Hi stephen:
>>
>> Stephen Hemminger said, at 2012/4/28 1:21:
>>
>>> Lots of options return more or different information based on kernel
>>> version, probably the biggest example is how stats are processed.
>>
>>
>> how about the following patch?
>>
>> ----
>> [PATCH] ss: use new INET_DIAG_SKMEMINFO option to get memory information for tcp socket
>>
>>
>> Signed-off-by: Shan Wei <[email-masked]>
>> ---
>>  misc/ss.c |   16 ++++++++++++++--
>>  1 files changed, 14 insertions(+), 2 deletions(-)
>>
>> diff --git a/misc/ss.c b/misc/ss.c
>> index 5f70a26..3cfc9e8 100644
>> --- a/misc/ss.c
>> +++ b/misc/ss.c
>> @@ -1336,7 +1336,17 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r)
>>  	parse_rtattr(tb, INET_DIAG_MAX, (struct rtattr*)(r+1),
>>  		     nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
>>  
>> -	if (tb[INET_DIAG_MEMINFO]) {
>> +	if (tb[INET_DIAG_SKMEMINFO]) {
>> +		const unsigned int *skmeminfo =  RTA_DATA(tb[INET_DIAG_SKMEMINFO]);
>> +		printf(" skmem:(r%u,rb%u,t%u,tb%u,f%u,w%u,o%u)",
>> +			skmeminfo[SK_MEMINFO_RMEM_ALLOC],
>> +			skmeminfo[SK_MEMINFO_RCVBUF],
>> +			skmeminfo[SK_MEMINFO_WMEM_ALLOC],
>> +			skmeminfo[SK_MEMINFO_SNDBUF],
>> +			skmeminfo[SK_MEMINFO_FWD_ALLOC],
>> +			skmeminfo[SK_MEMINFO_WMEM_QUEUED],
>> +			skmeminfo[SK_MEMINFO_OPTMEM]);
>> +	}else if (tb[INET_DIAG_MEMINFO]) {
>>  		const struct inet_diag_meminfo *minfo
>>  			= RTA_DATA(tb[INET_DIAG_MEMINFO]);
>>  		printf(" mem:(r%u,w%u,f%u,t%u)",
>> @@ -1505,8 +1515,10 @@ static int tcp_show_netlink(struct filter *f, FILE *dump_fp, int socktype)
>>  	memset(&req.r, 0, sizeof(req.r));
>>  	req.r.idiag_family = AF_INET;
>>  	req.r.idiag_states = f->states;
>> -	if (show_mem)
>> +	if (show_mem) {
>>  		req.r.idiag_ext |= (1<<(INET_DIAG_MEMINFO-1));
>> +		req.r.idiag_ext |= (1<<(INET_DIAG_SKMEMINFO-1));
>> +	}
>>  
>>  	if (show_tcpinfo) {
>>  		req.r.idiag_ext |= (1<<(INET_DIAG_INFO-1));
> 
> This looks good, is the skmeminfo a superset of the old meminfo?

In terms of the values it returns -- yes, but these two structures are not
binary compatible to each other.

> But your code is broken on 64 bit. skmeminfo in kernel is an array of __u32!

Hmm :( So is the inet_diag_meminfo, which was the prototype for the skmeminfo...
Should we introduce the SKMEMINFO64?

> .