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>>                                            p->flags |= PF_EXITING >>                                         exit_mm >>                                            p->mm = NULL; >> >>     migrate_swap_stop >>       __migrate_swap_task((arg->src_task, arg->dst_cpu) >>        count_memcg_event_mm(p->mm, NUMA_TASK_SWAP)# p->mm is NULL >> >> Could you please help check if the following debug patch works, > > Attached the patch: > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 8988d38d46a3..82fc966b390c 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -3364,7 +3364,12 @@ static void __migrate_swap_task(struct > task_struct *p, int cpu) >  { >      __schedstat_inc(p->stats.numa_task_swapped); >      count_vm_numa_event(NUMA_TASK_SWAP); > -    count_memcg_event_mm(p->mm, NUMA_TASK_SWAP); > +    if (unlikely(!p->mm)) { > +        trace_printk("!! (%d %s) flags=%lx\n", p->pid, p->comm, > +                p->flags); > +    } else { > +        count_memcg_event_mm(p->mm, NUMA_TASK_SWAP); > +    } > >      if (task_on_rq_queued(p)) { >          struct rq *src_rq, *dst_rq; I was encountering the same issue as mentioned earlier in this thread, which has been recurring in our daily linux-next CI builds within our virtualization CI stream where we observed this BUG appearing randomly during the runs. Additionally, we were able to reproduce this issue while running the autonuma benchmark. As mentioned earlier, the BUG would occur randomly across iterations, typically between the 5th and 10th iterations. We consistently encountered this issue up to the 6.16.0-rc4-next-20250630 build [https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git]. After applying the aforementioned patch ontop of next-20250630 build, I tested it in our virtualization CI and with the autonuma benchmark reproducer described below, and the issue no longer occurred. The patch appears to have resolved the reported problem. git clone https://github.com/pholasek/autonuma-benchmark.git cd autonuma-benchmark for i in $(seq 1 80); do bash ./start_bench.sh -s -t; done Note: The server running the autonuma-benchmark must have at least two nodes. If the provided fix is final, please feel free to include the following Tested-by tag: Tested-by: Srikanth Aithal Tested-by: Suneeth D