Bug #7563
netstat shows STREAMS memory statistics incorrect
Status:
New
Priority:
Low
Assignee:
-
Category:
cmd - userland programs
Start date:
2016-11-10
Due date:
% Done:
0%
Estimated time:
Difficulty:
Medium
Tags:
needs-triage
Description
On a high-load systems netstat -m shows the statistics incorrect.
In function m_report() the variable total_bytes cannot be negative,
this function uses kmem_cache_stats() to retrieve data from the kernel.
kstat_named_value() returns uint64_t values but we assign it to int variables
and on high-load systems they overflow.
viola% netstat -mv
streams allocation:
cumulative allocation
current maximum total failures
streams 125 190 420952 0
queues 289 360 769324 0
mblk 9232 215512 75119975 0
dblk_16 57 527 63113958 0
dblk_80 265 2820 2962822306 0
dblk_144 15 1800 2354804187 0
dblk_208 182 984 1670977 0
dblk_272 3 1090 682975 0
dblk_336 4 1104 252409 0
dblk_528 2 186 1160903 0
dblk_1040 0 203658 146710647 112
dblk_1488 0 145 13739695 0
dblk_1936 0 122 4606518 0
dblk_2576 0 582 3519923 0
dblk_3856 0 8 2048 0
dblk_8192 0 93 125149 0
dblk_12048 0 8 978 0
dblk_16384 0 62 16027 0
dblk_20240 0 7 42789 0
dblk_24576 0 31 104 0
dblk_28432 0 6 52 0
dblk_32768 0 31 49 0
dblk_36624 0 6 35 0
dblk_40960 0 31 28 0
dblk_44816 0 5 26 0
dblk_49152 0 31 24 0
dblk_53008 0 6 30 0
dblk_57344 0 31 14 0
dblk_61200 0 4 28 0
dblk_65536 0 62 782 0
dblk_69392 0 5 99 0
dblk_73728 0 31 34 0
dblk_esb 8704 8742 496565044 0
dblk_total 9232 222218 -2540096754 112
linkblk 9 83 10 0
syncq 8 25 29 0
qband 0 0 0 0
8619 Kbytes allocated for streams data
To solve this issue I offer you a patch, see the attach and this is the result:
viola% ./netstat -mv
streams allocation:
cumulative allocation
current maximum total failures
streams 125 190 421034 0
queues 289 360 769474 0
mblk 9605 215512 75165785 0
dblk_16 57 527 63155038 0
dblk_80 565 2820 7271559148 0
dblk_144 65 1800 2359978378 0
dblk_208 183 984 1671792 0
dblk_272 9 1090 683709 0
dblk_336 2 1104 253763 0
dblk_528 2 186 1163463 0
dblk_1040 0 203658 146823868 112
dblk_1488 0 145 13953448 0
dblk_1936 0 122 4676228 0
dblk_2576 0 582 3520081 0
dblk_3856 0 8 2048 0
dblk_8192 0 93 125151 0
dblk_12048 0 8 978 0
dblk_16384 0 62 16029 0
dblk_20240 0 7 42789 0
dblk_24576 0 31 104 0
dblk_28432 0 6 52 0
dblk_32768 0 31 49 0
dblk_36624 0 6 35 0
dblk_40960 0 31 28 0
dblk_44816 0 5 26 0
dblk_49152 0 31 24 0
dblk_53008 0 6 30 0
dblk_57344 0 31 14 0
dblk_61200 0 4 28 0
dblk_65536 0 62 782 0
dblk_69392 0 5 99 0
dblk_73728 0 31 34 0
dblk_esb 8704 8742 13409629498 0
dblk_total 9587 222218 23277256714 112
linkblk 9 83 10 0
syncq 8 25 29 0
qband 0 0 0 0
8689 Kbytes allocated for streams data
Maybe this tool has this issue somewhere else, I did not test it.
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