From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755977Ab3JGKi6 (ORCPT ); Mon, 7 Oct 2013 06:38:58 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39853 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753281Ab3JGKaL (ORCPT ); Mon, 7 Oct 2013 06:30:11 -0400 From: Mel Gorman To: Peter Zijlstra , Rik van Riel Cc: Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML , Mel Gorman Subject: [PATCH 31/63] mm: numa: only unmap migrate-on-fault VMAs Date: Mon, 7 Oct 2013 11:29:09 +0100 Message-Id: <1381141781-10992-32-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1381141781-10992-1-git-send-email-mgorman@suse.de> References: <1381141781-10992-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. [riel@redhat.com: Initial patch] Reviewed-by: Rik van Riel Reported-and-tested-by: Joe Mario Signed-off-by: Mel Gorman --- 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 b7052ed..1789e3c 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; -- 1.8.4