On 09/25/2015 01:27 PM, Joe Lawrence wrote: > On 09/24/2015 09:04 PM, Rik van Riel wrote: >> On 09/24/2015 05:14 PM, Joe Lawrence wrote: >>> [ +cc for linux-mm mailinglist address ] >>> >>> On 09/24/2015 05:08 PM, Joe Lawrence wrote: >>>> Hi Mel, Rik et al, >>>> >>>> We've encountered interesting NUMA balancing behavior on RHEL7.1, >>>> reproduced with an upstream 4.2 kernel (of similar .config), that can >>>> leave a user process trapped in the kernel performing task_numa_work. >>>> >>>> Our test group set up a server with 256GB memory running a program that >>>> allocates and dirties ~50% of that memory. They reported the following >>>> condition when they attempted to kill the test process -- the signal was >>>> never handled, instead traces showed the task stuck here: >> >> Does the bug still happen with this patch applied? >> >> https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=4620f8c1fda2af4ccbd11e194e2dd785f7d7f279 >> > > Hi Rik, > > Success! With 4620f8c1fda2 (-tip) cherry-picked on-top of 4.2, I could > successfully kill off the memory test process, even when the > numa_scan_period_max dropped to 140. > > I also ran kicked off the est program and let continue overnight (it > restarts itself after a given time) and several iterations ran without > incident. Glad to hear the issue is fixed in the latest -tip tree. FWIW, that fix is also slated to show up in the next RHEL 7 update. -- All rights reversed -- 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>