Messages in this thread | | | From | "Denys" <> | Subject | 2.6.21 -> 2.6.22 & 2.6.23-rc8 performance regression | Date | Sun, 30 Sep 2007 20:31:22 +0300 |
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P.S.S. I tried changing clocksource from acpi_pm to tsc. No difference. Tried to lock eth0 by smp_affinity to single CPU (no other interrups, except ioapic timer(LOC) there). No luck. I tried to change hashes in nf_conntrack, no difference. Tried to change eth0 weidht - no difference.
Also i notice, that exactly when softirqd start using CPU nearby 100% - problems happens.
At this time (with or without nice - the same, also the same to ping any host in network)
defaulthost ~ #nice -n -10 ping -s 10000 127.0.0.1 PING 127.0.0.1 (127.0.0.1) 10000(10028) bytes of data.
10008 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=377 ms 10008 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=328 ms 10008 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=329 ms 10008 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=355 ms 10008 bytes from 127.0.0.1: icmp_seq=5 ttl=64 time=0.047 ms
Delay value is ALWAYS nearby same. 350-360ms.
At same time if i ping "buggy 2.6.23-rc8" box, ping delay is perfect.
100000 packets transmitted, 100000 received, 0% packet loss, time 41793ms rtt min/avg/max/mdev = 0.027/0.127/1.439/0.095 ms, ipg/ewma 0.417/0.065 ms
There is nothing running except: squid, globax (TCP accelerator). Logs, disk cache on squid is disabled. Important note - there is conntract and REDIRECT used.
defaulthost /config #cat /proc/net/sockstat sockets: used 10670 TCP: inuse 12734 orphan 1390 tw 20248 alloc 12751 mem 9903 UDP: inuse 5 UDPLITE: inuse 0 RAW: inuse 0 FRAG: inuse 0 memory 0
defaulthost /config #cat /proc/net/softnet_stat 96c0060c 00000000 003fa90a 00000000 00000000 00000000 00000000 00000000 00000000 926120af 00000000 003e8692 00000000 00000000 00000000 00000000 00000000 00000000
defaulthost /config #cat /proc/net/ip_conntrack|wc -l 69256 (other host running 200K easily)
What can cause delays ~350-360ms for userspace applications?
-- Denys Fedoryshchenko Technical Manager Virtual ISP S.A.L.
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