mbuf denied problem

[Robert Watson]

On Mon, 22 May 2006, Robert Watson wrote:

>>>>> i have a problem with mbuf... when all my free memory is gone ( i have 
>>>>> 2gb ram) and memory allocation looks like this:
>>>> 
>>>> I recently received an informal problem report that there is a problem 
>>>> with the "denied" statistics gathering, so I think it's likely that's 
>>>> what is going on here.  I'll follow up with the submitter and see if we 
>>>> can't figure out something more definite.
>>> 
>>> I have received some further information on the problem from the reporter. 
>>> Could you give this patch a try and see what effect it has?
>> I already had made an identical patch and it worked.
>> 
>> This seems to be the problem.
>
> I have committed this patch as uma_core.c:1.137, and will MFC in a couple of 
> weeks assuming no additional problems are reported, and it seems to resolve 
> the issue.

Having received a number of positive reports regarding this patch, I've merged 
it to RELENG_6 as uma_core.c:1.119.2.15.  I will propose to re@ that this 
change be merged to RELENG_6_0 as an errata patch, as the problem has caused a 
number of reports.

Robert N M Watson

>
> Robert N M Watson
>
>>> 
>>> Index: uma_core.c
>>> ===================================================================
>>> RCS file: /home/ncvs/src/sys/vm/uma_core.c,v
>>> retrieving revision 1.136
>>> diff -u -r1.136 uma_core.c
>>> --- uma_core.c	11 Feb 2006 19:20:56 -0000	1.136
>>> +++ uma_core.c	21 May 2006 19:25:56 -0000
>>> @@ -2413,8 +2413,7 @@
>>>   	 * If nothing else caught this, we'll just do an internal free.
>>>   	 */
>>>   zfree_internal:
>>> -	uma_zfree_internal(zone, item, udata, SKIP_DTOR, ZFREE_STATFAIL |
>>> -	    ZFREE_STATFREE);
>>> +	uma_zfree_internal(zone, item, udata, SKIP_DTOR, ZFREE_STATFREE);
>>> 
>>>   	return;
>>>   }
>>> 
>>> Technically, there has been an allocation failure in this case in
>>> identifying a bucket to return the item to, but since the overall case is 
>>> a
>>> free, generating a failure statistics update seems undesirable.
>>> 
>>> Thanks,
>>> 
>>> Robert N M Watson
>>> 
>>>> Robert N M Watson
>>>> 
>>>>> Mem: 30M Active, 1607M Inact, 245M Wired, 84M Cache, 214M Buf, 3028K
>>>>> Free Swap: 695M Total, 695M Free
>>>>> 
>>>>> mbuf starts to deny...
>>>>> netstat -m show 0 deny till has memory, after that i see this:
>>>>> 
>>>>> Field root# netstat -m
>>>>> 629/466/1095 mbufs in use (current/cache/total)
>>>>> 512/176/688/65536 mbuf clusters in use (current/cache/total/max)
>>>>> 512/133 mbuf+clusters out of packet secondary zone in use
>>>>> (current/cache) 0/0/0/0 4k (page size) jumbo clusters in use
>>>>> (current/cache/total/max) 0/0/0/0 9k jumbo clusters in use
>>>>> (current/cache/total/max)
>>>>> 0/0/0/0 16k jumbo clusters in use (current/cache/total/max)
>>>>> 1181K/468K/1649K bytes allocated to network (current/cache/total)
>>>>> 7410219/101093/101499 requests for mbufs denied
>>>>> (mbufs/clusters/mbuf+clusters)
>>>>> 0/0/0 requests for jumbo clusters denied (4k/9k/16k)
>>>>> 0/0/0 sfbufs in use (current/peak/max)
>>>>> 0 requests for sfbufs denied
>>>>> 0 requests for sfbufs delayed
>>>>> 25288 requests for I/O initiated by sendfile
>>>>> 65 calls to protocol drain routines
>>>>> 
>>>>> this is my sysctl.conf:
>>>>> net.inet.tcp.delayed_ack=0
>>>>> net.inet.ip.intr_queue_maxlen=400
>>>>> net.inet.tcp.inflight.enable=0
>>>>> net.route.netisr_maxqlen=512
>>>>> kern.ipc.somaxconn=1024
>>>>> 
>>>>> should i attach any other conf/log,etc?
>>>>> thanks!
>>>>> _______________________________________________
>>>>> freebsd-net at freebsd.org mailing list
>>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-net
>>>>> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
>>>> 
>>>> _______________________________________________
>>>> freebsd-net at freebsd.org mailing list
>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-net
>>>> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
>>> 
>>> _______________________________________________
>>> freebsd-net at freebsd.org mailing list
>>> http://lists.freebsd.org/mailman/listinfo/freebsd-net
>>> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
>> 
>