On Fri, Dec 28, 2012 at 12:51 AM, Zlatko Calusic <zlatko.calusic@xxxxxxxx> wrote: > On 28.12.2012 00:42, Sedat Dilek wrote: >> >> On Fri, Dec 28, 2012 at 12:39 AM, Zlatko Calusic >> <zlatko.calusic@xxxxxxxx> wrote: >>> >>> On 28.12.2012 00:30, Sedat Dilek wrote: >>>> >>>> >>>> Hi Zlatko, >>>> >>>> I am not sure if I hit the same problem as described in this thread. >>>> >>>> Under heavy load, while building a customized toolchain for the Freetz >>>> router project I got a BUG || NULL pointer derefence || kswapd || >>>> zone_balanced || pgdat_balanced() etc. (details see my screenshot). >>>> >>>> I will try your patch from [1] ***only*** on top of my last >>>> Linux-v3.8-rc1 GIT setup (post-v3.8-rc1 mainline + some net-fixes). >>>> >>> >>> Yes, that's the same bug. It should be fixed with my latest patch, so I'd >>> appreciate you testing it, to be on the safe side this time. There should >>> be >>> no difference if you apply it to anything newer than 3.8-rc1, so go for >>> it. >>> Thanks! >>> >> >> Not sure how I can really reproduce this bug as one build worked fine >> within my last v3.8-rc1 kernel. >> I increased the parallel-make-jobs-number from "4" to "8" to stress a >> bit harder. >> Just building right now... and will report. >> >> If you have any test-case (script or whatever), please let me/us know. >> > > Unfortunately not, I haven't reproduced it yet on my machines. But it seems > that bug will hit only under heavy memory pressure. When close to OOM, or > possibly with lots of writing to disk. It's also possible that fragmentation > of memory zones could provoke it, that means testing it for a longer time. > I tested successfully by doing simultaneously... - building Freetz with 8 parallel make-jobs - building Linux GIT with 1 make-job - 9 tabs open in firefox - In one tab I ran YouTube music video - etc. I am reading [1] and [2] where another user reports success by reverting this... commit cda73a10eb3f493871ed39f468db50a65ebeddce "mm: do not sleep in balance_pgdat if there's no i/o congestion" BTW, this machine has also 4GiB RAM (Ubuntu/precise AMD64). Feel free to add a "Reported-by/Tested-by" if you think this is a positive report. - Sedat - [1] http://marc.info/?l=linux-mm&m=135652835931174&w=2 [2] http://marc.info/?l=linux-mm&m=135653399800655&w=2 > -- > Zlatko -- 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>