Subject: Re: possible kernel bug: stat mclpl after heavy net load
To: Pavel Cahyna <pavel.cahyna@st.mff.cuni.cz>
From: Stephan Pietzko <netbsd@wiki.uni-konstanz.de>
List: current-users
Date: 12/17/2005 08:01:41
Pavel Cahyna <pcah8322@artax.karlin.mff.cuni.cz> wrote
> > > 
> > > I see a very similiar thing, but with nfsd rather than httpd, and on an
> > > x86 system running current from this past weekend.  And it's after
> > > very heavy nfs load.
> > Than it would be a general kernel-bug in the network memory pool?!
> > How can i debug the problem or get more information about it?
> > 
> > For now i wait for the next crash. 

In the meantime i had the next crash. After around 800G uploadtraffic.
GENERIC-kernel, netbsd-2 build form the source (6. dec), thttpd with
high load. In crashed state (thttpd hangs not killable with -9, rest
works) i made ps -aux, lsof -i, vmstat -m, netstat -m, in addition i
have greped netstat -m and mbpl and mclpl out of vmstat -m every 10
minutes. 
What info is interesting vor debugging?

> compile a kernel with 'options SOSEND_NO_LOAN' ?

Ok - i try this

tnx Stephan
----------------------------------------------------------------------
here some outputs

line of thttpd from ps -aux
www    307  0.0  0.0 2416 163208 ??  DWNs Wed08PM 508:30.23 /usr/pkg/sbin/thttpd -C /usr/pkg/etc/thttpd.conf 

10min log from vmstat -m | grep mbpl around the crash (the number bevor the hour is the day)
16.16:00:00 mbpl         256  5019435    0  5016533  2445  2326   119   163     1   inf    0
16.16:10:00 mbpl         256  5045161    0  5041878  2445  2331   114   163     1   inf    0
16.16:20:01 mbpl         256  5067090    0  5063567  2452  2332   120   163     1   inf    0
16.16:30:00 mbpl         256  5089980    0  5086830  2454  2335   119   163     1   inf    0
16.16:40:00 mbpl         256  5105932    0  5102777  2455  2338   117   163     1   inf    0
16.16:50:01 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.17:00:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.17:10:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.17:20:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.17:30:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.17:40:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.17:50:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.18:00:01 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.18:10:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.18:20:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.18:30:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.18:40:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.18:50:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.19:00:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.19:10:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.19:20:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.19:30:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.19:40:01 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.19:50:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.20:00:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.20:10:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.20:20:00 mbpl         256  5115475    0  5110123  2513  2339   174   174     1   inf    1
16.20:30:00 mbpl         256      606    0        0    21     0    21    21     1   inf    1
16.20:40:00 mbpl         256     1017    0      251    27     1    26    26     1   inf    1
16.20:50:01 mbpl         256     2853    0     1187    61     3    58    58     1   inf    0
16.21:00:00 mbpl         256     4563    0     2730    69     5    64    65     1   inf    0
16.21:10:00 mbpl         256     6568    0     4604    77     6    71    71     1   inf    0
16.21:20:00 mbpl         256     9267    0     6726    90     7    83    83     1   inf    1
16.21:30:00 mbpl         256    11069    0     9091    90     8    82    83     1   inf    0
16.21:40:00 mbpl         256    13081    0    11107    90     9    81    83     1   inf    0
16.21:50:00 mbpl         256    15754    0    14123    90    12    78    83     1   inf    1
16.22:00:00 mbpl         256    20872    0    18389    94    13    81    83     1   inf    0
16.22:10:00 mbpl         256    26631    0    24500   101    15    86    87     1   inf    0
16.22:20:01 mbpl         256    31364    0    29014   101    15    86    87     1   inf    1
16.22:30:00 mbpl         256    39026    0    36182   118    17   101   101     1   inf    0
16.22:40:00 mbpl         256    45350    0    42404   118    18   100   101     1   inf    0
16.22:50:00 mbpl         256    51812    0    48785   120    19   101   101     1   inf    0
16.23:00:01 mbpl         256    58597    0    55446   123    20   103   103     1   inf    0
16.23:10:00 mbpl         256    67293    0    65211   135    22   113   114     1   inf    0
16.23:20:00 mbpl         256    77051    0    73815   135    23   112   114     1   inf    0
16.23:30:00 mbpl         256    83872    0    80665   135    25   110   114     1   inf    0
16.23:40:00 mbpl         256    89073    0    85984   135    25   110   114     1   inf    0
16.23:50:00 mbpl         256    97270    0    94117   135    27   108   114     1   inf    0
17.00:00:01 mbpl         256   103246    0   100352   138    28   110   114     1   inf    0
17.00:10:01 mbpl         256   108555    0   105895   138    30   108   114     1   inf    0
17.00:20:01 mbpl         256   113704    0   110971   138    32   106   114     1   inf    0
17.00:30:00 mbpl         256   119028    0   116019   138    34   104   114     1   inf    0
17.00:40:00 mbpl         256   123046    0   120908   139    35   104   114     1   inf    0
17.00:50:00 mbpl         256   125585    0   123430   139    36   103   114     1   inf    0

same with mclpl
16.16:00:00 mclpl       2048   936092    0   935569 32001 31862   139   218     2   256    4
16.16:10:00 mclpl       2048   941561    0   940912 32098 31932   166   218     2   256    0
16.16:20:01 mclpl       2048   947167    0   946444 32177 31991   186   218     2   256    0
16.16:30:00 mclpl       2048   951872    0   951229 32235 32060   175   218     2   256    2
16.16:40:00 mclpl       2048   955126    0   954505 32272 32109   163   218     2   256    1
16.16:50:01 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.17:00:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.17:10:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.17:20:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.17:30:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.17:40:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.17:50:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.18:00:01 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.18:10:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.18:20:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.18:30:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.18:40:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.18:50:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.19:00:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.19:10:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.19:20:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.19:30:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.19:40:01 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.19:50:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.20:00:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.20:10:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.20:20:00 mclpl       2048   957082    0   956070 32378 32125   253   253     2   256    0
16.20:30:00 mclpl       2048      118    0        0    32     0    32    32     2   256    2
16.20:40:00 mclpl       2048      210    0       59    45     5    40    40     2   256    2
16.20:50:01 mclpl       2048      592    0      265    98    13    85    87     2   256    0
16.21:00:00 mclpl       2048      891    0      480   126    21   105   105     2   256    2
16.21:10:00 mclpl       2048     1212    0      802   149    34   115   117     2   256    0
16.21:20:00 mclpl       2048     1741    0     1216   178    44   134   134     2   256    2
16.21:30:00 mclpl       2048     2162    0     1732   178    52   126   134     2   256    1
16.21:40:00 mclpl       2048     2587    0     2139   181    66   115   134     2   256    0
16.21:50:00 mclpl       2048     3213    0     2907   205    78   127   134     2   256    8
16.22:00:00 mclpl       2048     4315    0     3768   228    89   139   139     2   256    2
16.22:10:00 mclpl       2048     5291    0     4787   240   103   137   141     2   256    0
16.22:20:01 mclpl       2048     6200    0     5704   250   119   131   141     2   256    0
16.22:30:00 mclpl       2048     7522    0     6960   289   137   152   154     2   256    0
16.22:40:00 mclpl       2048     8776    0     8186   301   151   150   154     2   256    2
16.22:50:00 mclpl       2048     9929    0     9469   322   166   156   159     2   256    3
16.23:00:01 mclpl       2048    11142    0    10516   337   178   159   160     2   256    1
16.23:10:00 mclpl       2048    12814    0    12416   368   201   167   169     2   256   31
16.23:20:00 mclpl       2048    14636    0    14005   375   211   164   174     2   256    1
16.23:30:00 mclpl       2048    15794    0    15176   382   222   160   174     2   256    0
16.23:40:00 mclpl       2048    16729    0    16119   385   230   155   174     2   256    2
16.23:50:00 mclpl       2048    18099    0    17475   404   246   158   174     2   256    2
17.00:00:01 mclpl       2048    19189    0    18593   421   260   161   174     2   256    2
17.00:10:01 mclpl       2048    20329    0    19783   424   279   145   174     2   256    0
17.00:20:01 mclpl       2048    21364    0    20806   438   289   149   174     2   256    0
17.00:30:00 mclpl       2048    22431    0    21823   460   306   154   174     2   256    1
17.00:40:00 mclpl       2048    23255    0    22762   475   327   148   174     2   256    1
17.00:50:00 mclpl       2048    23728    0    23254   475   344   131   174     2   256    0

same with netstat -m only data
16.16:00:00 793 mbufs in use: 717 mbufs allocated to data
16.16:10:00 1070 mbufs in use: 1000 mbufs allocated to data
16.16:20:01 1620 mbufs in use: 1549 mbufs allocated to data
16.16:30:00 1247 mbufs in use: 1179 mbufs allocated to data
16.16:40:00 1578 mbufs in use: 1514 mbufs allocated to data
16.16:50:01 820 mbufs in use: 633 mbufs allocated to data
16.17:00:00 977 mbufs in use: 741 mbufs allocated to data
16.17:10:00 976 mbufs in use: 741 mbufs allocated to data
16.17:20:00 975 mbufs in use: 741 mbufs allocated to data
16.17:30:00 974 mbufs in use: 741 mbufs allocated to data
16.17:40:00 974 mbufs in use: 741 mbufs allocated to data
16.17:50:00 973 mbufs in use: 741 mbufs allocated to data
16.18:00:01 899 mbufs in use: 668 mbufs allocated to data
16.18:10:00 899 mbufs in use: 668 mbufs allocated to data
16.18:20:00 899 mbufs in use: 668 mbufs allocated to data
16.18:30:00 899 mbufs in use: 668 mbufs allocated to data
16.18:40:00 899 mbufs in use: 668 mbufs allocated to data
16.18:50:00 899 mbufs in use: 668 mbufs allocated to data
16.19:00:00 899 mbufs in use: 668 mbufs allocated to data
16.19:10:00 899 mbufs in use: 668 mbufs allocated to data
16.19:20:00 898 mbufs in use: 668 mbufs allocated to data
16.19:30:00 898 mbufs in use: 668 mbufs allocated to data
16.19:40:01 898 mbufs in use: 668 mbufs allocated to data
16.19:50:00 898 mbufs in use: 668 mbufs allocated to data
16.20:00:00 898 mbufs in use: 668 mbufs allocated to data
16.20:10:00 898 mbufs in use: 668 mbufs allocated to data
16.20:20:00 898 mbufs in use: 668 mbufs allocated to data
16.20:30:00 466 mbufs in use: 455 mbufs allocated to data
16.20:40:00 537 mbufs in use: 526 mbufs allocated to data
16.20:50:01 1017 mbufs in use: 986 mbufs allocated to data
16.21:00:00 1465 mbufs in use: 1428 mbufs allocated to data
16.21:10:00 1496 mbufs in use: 1456 mbufs allocated to data
16.21:20:00 1561 mbufs in use: 1516 mbufs allocated to data
16.21:30:00 1320 mbufs in use: 1278 mbufs allocated to data
16.21:40:00 1391 mbufs in use: 1349 mbufs allocated to data
16.21:50:00 1220 mbufs in use: 1174 mbufs allocated to data
16.22:00:00 945 mbufs in use: 889 mbufs allocated to data
16.22:10:00 914 mbufs in use: 872 mbufs allocated to data
16.22:20:01 1381 mbufs in use: 1334 mbufs allocated to data
16.22:30:00 1553 mbufs in use: 1499 mbufs allocated to data
16.22:40:00 2198 mbufs in use: 2142 mbufs allocated to data
16.22:50:00 1546 mbufs in use: 1491 mbufs allocated to data
16.23:00:01 1097 mbufs in use: 1040 mbufs allocated to data
16.23:10:00 399 mbufs in use: 335 mbufs allocated to data
16.23:20:00 1343 mbufs in use: 1283 mbufs allocated to data
16.23:30:00 2071 mbufs in use: 2013 mbufs allocated to data
16.23:40:00 1539 mbufs in use: 1482 mbufs allocated to data
16.23:50:00 2160 mbufs in use: 2101 mbufs allocated to data
17.00:00:01 1318 mbufs in use: 1263 mbufs allocated to data
17.00:10:01 1463 mbufs in use: 1415 mbufs allocated to data
17.00:20:01 1761 mbufs in use: 1712 mbufs allocated to data
17.00:30:00 1686 mbufs in use: 1630 mbufs allocated to data
17.00:40:00 1104 mbufs in use: 1064 mbufs allocated to data
17.00:50:00 1287 mbufs in use: 1246 mbufs allocated to data