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Before submitting this patch, > I had two internal proposals: lock and cmpxchg. Here is the my cmpxchg > version (Test passed). If you're ok with this cmpxchg version, may I have > your reviewed-by? I'll send a v2 then. > > --- > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 3356315d7e64..7f99df294583 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -3399,10 +3399,16 @@ static void task_numa_work(struct callback_head *work) > > /* Initialise new per-VMA NUMAB state. */ > if (!vma->numab_state) { > - vma->numab_state = kzalloc(sizeof(struct vma_numab_state), > - GFP_KERNEL); > - if (!vma->numab_state) > + struct vma_numab_state *ptr; > + > + ptr = kzalloc(sizeof(*ptr), GFP_KERNEL); > + if (!ptr) > + continue; > + > + if (cmpxchg(&vma->numab_state, NULL, ptr)) { > + kfree(ptr); > continue; > + } > > vma->numab_state->start_scan_seq = mm->numa_scan_seq; > LGTM. Sure feel free to add Reviewed-by: Raghavendra K T Since allocation for numab_state happen only once.. I hope there is not much impact on the performance also. Thanks and Regards - Raghu