On Fri, 1 Jul 2005, Eric Anderson wrote: > Eric Anderson wrote: >> Andre Guibert de Bruet wrote: >>> On Thu, 16 Jun 2005, Eric Anderson wrote: >>>> M. Warner Losh wrote: >>>>> In message: <20050616075743.GE2239_at_obiwan.tataz.chchile.org> >>>>> Jeremie Le Hen <jeremie_at_le-hen.org> writes: >>>>> : > : May you delve into this a little bit more please ? The ping(8) >>>>> manual >>>>> : > : page states that the -i flags makes ping(8) to wait a given couple >>>>> of >>>>> : > : seconds. If I use the flags "-i 1", I expect ECHO Requests to be >>>>> sent >>>>> : > : with one second between each, whatever the AC line status is. >>>>> : > : (Note that I didn't explicitely specified "-i 1" in the above >>>>> example, >>>>> : > : but this doesn't change the behaviour.) >>>>> : > : > Well, the rount trip times went way up (3x longer). That's >>>>> normal for >>>>> : > a 200MHz CPU... My 333MHz EISA machine can't do much better than >>>>> : > that. >>>>> : > : > But the 2.252s run time is a little longish. Do you see this >>>>> : > consistantly? If you ran it a second time would you get identical >>>>> : > results. I've seen ARP take a while... What else do you have >>>>> running >>>>> : > on the system? Maybe a daemon that takes almost no time at 1.7GHz >>>>> : > takes a lot longer at 200Mhz and that's starving the ping process... >>>>> : > Or some driver has gone insane... >>>>> : : Yes, I ran this test multiple times, and I almost get always this >>>>> same >>>>> : result although I got 2.208s sometimes, but I don't think this is >>>>> : significant. >>>>> : : FYI, >>>>> : my powerd(8) is configured to tastes AC-line four times per seconds. >>>>> : I tried reducing it's freqency from 4 to 1, but it doesn't change >>>>> : anything. >>>>> : : ARP is not the culprit, the MAC address is already in cache. >>>>> : : My kernel is compiled with INVARIANTS, but I don't have WITNESS. My >>>>> : network interface uses the bge(4) driver. No firewall rule or complex >>>>> : network setup. >>>>> : : Anyway this doesn't hurt much. Thanks for lightening me. >>>>> >>>>> Dang, I was hoping it was one of the easy explainations.... Maybe it >>>>> is the idle code not waking up fast enough when it has been asleep for >>>>> a bit. But that's pure speculation at this point... >>>> >>>> Another datapoint - running -CURRENT as of about June 7th, I see this >>>> too: >>>> >>>> $ time ping -i 1 -c 5 localhost >>>> PING localhost (127.0.0.1): 56 data bytes >>>> 64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.041 ms >>>> 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.033 ms >>>> 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.029 ms >>>> 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.031 ms >>>> 64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.035 ms >>>> >>>> --- localhost ping statistics --- >>>> 5 packets transmitted, 5 packets received, 0% packet loss >>>> round-trip min/avg/max/stddev = 0.029/0.034/0.041/0.004 ms >>>> >>>> real 0m9.728s >>>> user 0m0.000s >>>> sys 0m0.003s >>>> >>>> On a 5-STABLE machine: >>>> $ time ping -i 1 -c 5 localhost >>>> PING localhost (127.0.0.1): 56 data bytes >>>> 64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.049 ms >>>> 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.032 ms >>>> 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.024 ms >>>> 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.021 ms >>>> 64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.032 ms >>>> >>>> --- localhost ping statistics --- >>>> 5 packets transmitted, 5 packets received, 0% packet loss >>>> round-trip min/avg/max/stddev = 0.021/0.032/0.049/0.010 ms >>>> >>>> real 0m4.064s >>>> user 0m0.000s >>>> sys 0m0.005s >>>> >>>> I have powerd running, but it makes no difference whether I have it >>>> running or not, nor does it make any difference if I'm on ac or battery. >>>> >>>> This worked fine a couple weeks back for me - the only thing I recall >>>> changing is adding apic to my kernel. >>> >>> Just out of curiosity, does removing debugging options from your kernel >>> config change anything? >> >> Nope. And setting my scheduler back (from ULE) doesn't help either.. >> >> I'm thinking it must be a module, or something else I have installed. I >> have set up another laptop just like mine, and it does not show the issue. >> I'm still trying to track it down. > > After looking a little more, I noticed that booting into 'safemode' seems to > get rid of the delay. Here's a snippet of a sysctl diff between two boots: > > 259,260c249,250 > < kern.timecounter.hardware: ACPI-fast > < kern.timecounter.choice: TSC(800) ACPI-fast(1000) i8254(0) dummy(-1000000) > --- >> kern.timecounter.hardware: TSC >> kern.timecounter.choice: TSC(800) i8254(0) dummy(-1000000) > > I have apic in my kernel config, and I think teh safemode disables apic and > acpi. I'm guessing it's an apic issue? What do the respective outputs of vmstat -i look like for either kernel? Andy /* Andre Guibert de Bruet * 6f43 6564 7020 656f 2e74 4220 7469 6a20 */ /* Code poet / Sysadmin * 636f 656b 2e79 5320 7379 6461 696d 2e6e */ /* GSM: +1 734 846 8758 * 5520 494e 2058 6c73 7565 6874 002e 0000 */ /* WWW: siliconlandmark.com * Tormenting bytes since 1980. */Received on Wed Jul 06 2005 - 17:15:19 UTC
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