Fengguang, Maybe it's because zone_reclaim_mode? We often have received some reports that scp or something like that is slow with no reason, and mostly it's due to someone enabled zone_reclaim_mode by mistake. Stefan, is your zone_reclaim_mode enabled? try 'cat /proc/sys/vm/zone_reclaim_mode', and echo 0 to it to disable. Thanks, Zhu Yanhai 2011/8/26 Wu Fengguang <fengguang.wu@xxxxxxxxx>: > 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 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href