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From: Alexey Vlasov <renton@renton.name>
To: linux-kernel@vger.kernel.org
Subject: 2.6.36.2 - loop on read /proc/net/tcp
Date: Wed, 22 Dec 2010 16:43:43 +0300	[thread overview]
Message-ID: <20101222134343.GC19998@beaver.vrungel.ru> (raw)

Hi.

Has anyone seen such a bug at 2.6.36.2?
# netstat -ntl
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 81.176.228.2:60608      0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:8099       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.5:8099       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.7:8099       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:8100       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.5:8100       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:8101       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.5:8101       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.5:20037      0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:8102       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.5:8102       0.0.0.0:*               LISTEN
tcp        0      0 127.0.0.1:3399          0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:20040      0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:38985      0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:873             0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:20041      0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:20042      0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:3306       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.3:3306       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.2:3306       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.5:9099       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:9099       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:20043      0.0.0.0:*               LISTEN
tcp        0      0 0.0.0.0:139             0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.5:9100       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:9100       0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:20044      0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.5:33549      0.0.0.0:*               LISTEN
...
First 30 lines are ok

but then go lines repeating in "eternal" loop:
tcp        0      0 81.176.228.2:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.3:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.7:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.2:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.3:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.7:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.2:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.3:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.4:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.7:80         0.0.0.0:*               LISTEN
tcp        0      0 81.176.228.2:80         0.0.0.0:*               LISTEN

# cat /proc/net/tcp
...
It can hang an hour or so. but not always actually.

# i=0; while [ "$i" -lt "10" ]; do time wc -l /proc/net/tcp; let "i = $i + 1"; done
614782727 /proc/net/tcp

real    18m42.066s
user    0m12.620s
sys     18m25.890s
19443 /proc/net/tcp

real    0m0.040s
user    0m0.000s
sys     0m0.030s
19503 /proc/net/tcp

real    0m0.040s
sys     0m0.030s
19502 /proc/net/tcp

real    0m0.041s
user    0m0.000s
sys     0m0.040s
28525 /proc/net/tcp

real    0m0.059s
user    0m0.000s
sys     0m0.050s
19463 /proc/net/tcp

real    0m0.048s
user    0m0.000s
sys     0m0.040s
19521 /proc/net/tcp

real    0m0.040s
user    0m0.000s
sys     0m0.030s
54394 /proc/net/tcp

real    0m0.104s
user    0m0.000s
sys     0m0.100s
19479 /proc/net/tcp

real    0m0.040s
user    0m0.000s
sys     0m0.030s
19481 /proc/net/tcp

real    0m0.040s
user    0m0.000s
sys     0m0.030s

-- 
BRGDS. Alexey Vlasov.

             reply	other threads:[~2010-12-22 14:07 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-22 13:43 Alexey Vlasov [this message]
2010-12-22 16:54 ` Eric Dumazet
2010-12-23  5:07 ` Eric Dumazet
2010-12-23 17:33   ` David Miller

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