task_numa_placement checks current->mm but after buffers for faults have already been uselessly allocated. Move the check earlier.
[[email protected]: Identified the problem] Signed-off-by: Mel Gorman <[email protected]> --- kernel/sched/fair.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 336074f..3c796b0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -870,8 +870,6 @@ static void task_numa_placement(struct task_struct *p) int seq, nid, max_nid = 0; unsigned long max_faults = 0; - if (!p->mm) /* for example, ksmd faulting in a user's mm */ - return; seq = ACCESS_ONCE(p->mm->numa_scan_seq); if (p->numa_scan_seq == seq) return; @@ -945,6 +943,12 @@ void task_numa_fault(int last_nid, int node, int pages, bool migrated) if (!sched_feat_numa(NUMA)) return; + /* for example, ksmd faulting in a user's mm */ + if (!p->mm) { + p->numa_scan_period = sysctl_numa_balancing_scan_period_max; + return; + } + /* Allocate buffer to track faults on a per-node basis */ if (unlikely(!p->numa_faults)) { int size = sizeof(*p->numa_faults) * 2 * nr_node_ids; @@ -1072,16 +1076,18 @@ void task_numa_work(struct callback_head *work) end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE); end = min(end, vma->vm_end); nr_pte_updates += change_prot_numa(vma, start, end); - pages -= (end - start) >> PAGE_SHIFT; - - start = end; /* * Scan sysctl_numa_balancing_scan_size but ensure that - * least one PTE is updated so that unused virtual - * address space is quickly skipped + * at least one PTE is updated so that unused virtual + * address space is quickly skipped. */ - if (pages <= 0 && nr_pte_updates) + if (nr_pte_updates) + pages -= (end - start) >> PAGE_SHIFT; + + start = end; + + if (pages <= 0) goto out; } while (end != vma->vm_end); } -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
