Messages in this thread | | | Date | Fri, 26 Aug 2011 11:26:02 +0800 | From | Wu Fengguang <> | Subject | Re: slow performance on disk/network i/o full speed after drop_caches |
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On Fri, Aug 26, 2011 at 11:13:07AM +0800, Stefan Priebe wrote: > > >> There is at least a numastat proc file. > > > > Thanks. This shows that node0 is accessed 10x more than node1. > > What can i do to prevent this or isn't this normal when a machine mostly idles so processes are mostly processed by cpu0.
Yes, that's normal. However it should explain why it's slow even when there are lots of free pages _globally_.
> > > >> complete ps output: > >> http://pastebin.com/raw.php?i=b948svzN > > > > In that log, scp happens to be in R state and also no other tasks in D > > state. Would you retry in the hope of catching some stucked state? > Sadly not as the sysrq trigger has rebootet the machine and it will now run fine for 1 or 2 days.
Oops, sorry! It might be possible to reproduce the issue by manually eating all of the memory with sparse file data:
truncate -s 1T 1T cp 1T /dev/null
> > > >>> echo t> /proc/sysrq-trigger > >> sadly i wa sonly able to grab the output in this crazy format: > >> http://pastebin.com/raw.php?i=MBXvvyH1 > > > > It's pretty readable dmesg, except that the data is incomplete and > > there are nothing valuable in the uploaded portion.. > That was everything i could grab through netconsole. Is there a better way?
netconsole is enough. The partial output should be due to the reboot...
Thanks, Fengguang
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