Messages in this thread | | | Date | Wed, 27 Aug 2008 20:35:18 -0700 | From | Stephen Hemminger <> | Subject | Re: loaded router, excessive getnstimeofday in oprofile |
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On Fri, 22 Aug 2008 04:57:40 +0300 Denys Fedoryshchenko <denys@visp.net.lb> wrote:
> I have loaded router (~650 Mbps In+Out), based on 2xAMD Opteron 248, Sun Fire > X4100. HPET timer available (TSC seems not available on this platform). > Network interfaces is onboard, connected over PCI-X. > > Right now i am using only one processor, cause using only one interface and > interrupts stick to it. Other is almost not used. > At peak time i notice in mpstat, that this processor is almost "dead", and if > i run minor application consuming resources - ping over this router will be > terrible. For me it is clear - system overloaded. I did oprofile, and here is > result (at low load time, but at peak time it is very similar). > > CPU: AMD64 processors, speed 2193.74 MHz (estimated) > Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit > mask of 0x00 (No unit mask) count 100000 > CPU_CLK_UNHALT...| > samples| %| > ------------------ > 2679376 71.9851 vmlinux > 287212 7.7163 e1000 > 278674 7.4870 ip_tables > 259923 6.9832 nf_conntrack > 29699 0.7979 iptable_nat > 26752 0.7187 nf_nat > 26093 0.7010 nf_conntrack_ipv4 > 16525 0.4440 iptable_mangle > 14988 0.4027 oprofiled > > > CPU: AMD64 processors, speed 2193.74 MHz (estimated) > Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit > mask of 0x00 (No unit mask) count 100000 > samples % symbol name > 1031727 37.1736 getnstimeofday > 230457 8.3035 __napi_schedule > 122154 4.4013 __do_softirq > 110036 3.9647 dev_queue_xmit > 88800 3.1995 net_rx_action > 71163 2.5640 ip_route_input > 52232 1.8819 local_bh_enable > 43804 1.5783 get_next_timer_interrupt > 43387 1.5633 ip_forward > 35501 1.2791 nf_iterate > 35212 1.2687 __slab_alloc > 34652 1.2485 default_idle > 32375 1.1665 kfree > 28127 1.0134 kmem_cache_alloc > > What is bothering me, why getnstimeofday called so much? Even i remove HTB > shaper, it still takes 30-40% of whole vmlinux time. From other > applications - only zebra is running. > Any ideas?
What kernel version is this? There was a fix to AF_PACKET about a year ago to reduce this.
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