>On 11 March 2013 13:15, Michal Suchanek <hramrach@xxxxxxxxx> wrote: >>On 8 February 2013 17:31, Michal Suchanek <hramrach@xxxxxxxxx> wrote: >> Hello, >> >> I am dealing with VM disk images and performing something like wiping >> free space to prepare image for compressing and storing on server or >> copying it to external USB disk causes >> >> 1) system lockup in order of a few tens of seconds when all CPU cores >> are 100% used by system and the machine is basicaly unusable >> >> 2) oom killer killing processes >> >> This all on system with 8G ram so there should be plenty space to work with. >> >> This happens with kernels 3.6.4 or 3.7.1 >> >> With earlier kernel versions (some 3.0 or 3.2 kernels) this was not a >> problem even with less ram. >> >> I have vm.swappiness = 0 set for a long time already. >> >> >I did some testing with 3.7.1 and with swappiness as much as 75 the >kernel still causes all cores to loop somewhere in system when writing >lots of data to disk. > >With swappiness as much as 90 processes still get killed on large disk writes. > >Given that the max is 100 the interval in which mm works at all is >going to be very narrow, less than 10% of the paramater range. This is >a severe regression as is the cpu time consumed by the kernel. > >The io scheduler is the default cfq. > >If you have any idea what to try other than downgrading to an earlier >unaffected kernel I would like to hear. > Can you try commit 3cf23841b4b7(mm/vmscan.c: avoid possible deadlock caused by too_many_isolated())? Or try 3.8 and/or 3.9, additionally? Hillf -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>