Commit-ID: fc3147245d193bd0f57307859c698fa28a20b0fe Gitweb: http://git.kernel.org/tip/fc3147245d193bd0f57307859c698fa28a20b0fe Author: Mel Gorman <[email protected]> AuthorDate: Mon, 7 Oct 2013 11:29:09 +0100 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 9 Oct 2013 12:40:38 +0200
mm: numa: Limit NUMA scanning to migrate-on-fault VMAs There is a 90% regression observed with a large Oracle performance test on a 4 node system. Profiles indicated that the overhead was due to contention on sp_lock when looking up shared memory policies. These policies do not have the appropriate flags to allow them to be automatically balanced so trapping faults on them is pointless. This patch skips VMAs that do not have MPOL_F_MOF set. [[email protected]: Initial patch] Signed-off-by: Mel Gorman <[email protected]> Reported-and-tested-by: Joe Mario <[email protected]> Reviewed-by: Rik van Riel <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Srikar Dronamraju <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- include/linux/mempolicy.h | 1 + kernel/sched/fair.c | 2 +- mm/mempolicy.c | 24 ++++++++++++++++++++++++ 3 files changed, 26 insertions(+), 1 deletion(-) diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index da6716b..ea4d249 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -136,6 +136,7 @@ struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp, struct mempolicy *get_vma_policy(struct task_struct *tsk, struct vm_area_struct *vma, unsigned long addr); +bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma); extern void numa_default_policy(void); extern void numa_policy_init(void); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 61ec0d4..d98175d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1130,7 +1130,7 @@ void task_numa_work(struct callback_head *work) vma = mm->mmap; } for (; vma; vma = vma->vm_next) { - if (!vma_migratable(vma)) + if (!vma_migratable(vma) || !vma_policy_mof(p, vma)) continue; do { diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 196d8da..0e895a2 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1679,6 +1679,30 @@ struct mempolicy *get_vma_policy(struct task_struct *task, return pol; } +bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma) +{ + struct mempolicy *pol = get_task_policy(task); + if (vma) { + if (vma->vm_ops && vma->vm_ops->get_policy) { + bool ret = false; + + pol = vma->vm_ops->get_policy(vma, vma->vm_start); + if (pol && (pol->flags & MPOL_F_MOF)) + ret = true; + mpol_cond_put(pol); + + return ret; + } else if (vma->vm_policy) { + pol = vma->vm_policy; + } + } + + if (!pol) + return default_policy.flags & MPOL_F_MOF; + + return pol->flags & MPOL_F_MOF; +} + static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone) { enum zone_type dynamic_policy_zone = policy_zone; -- 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/
