Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933209AbbFCPC0 (ORCPT ); Wed, 3 Jun 2015 11:02:26 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:51338 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S933090AbbFCPBm (ORCPT ); Wed, 3 Jun 2015 11:01:42 -0400 X-IronPort-AV: E=Sophos;i="5.01,1,1399996800"; d="scan'208";a="96378547" From: Lai Jiangshan To: CC: Lai Jiangshan , Tejun Heo Subject: [PATCH 2/4] workqueue: reuse the current per-node pwq when its attrs are unchanged Date: Wed, 3 Jun 2015 22:29:50 +0800 Message-ID: <1433341792-2017-3-git-send-email-laijs@cn.fujitsu.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1433341792-2017-1-git-send-email-laijs@cn.fujitsu.com> References: <1433341792-2017-1-git-send-email-laijs@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.167.226.103] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2550 Lines: 71 If the cpumask is changed, it is possible that only a part of the per-node pwq is affected. This can happen when the user changes the cpumask of a workqueue or the low level cpumask. So we try to reuse the current per-node pwq when its attrs are unchanged. In wq_update_unbound_numa(), we had already made the current pwq be reused when its attrs are unaffected, but we move the code of fetching current pwq closer to the code of testing. Signed-off-by: Lai Jiangshan --- kernel/workqueue.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 6aa9bd5..197520b 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -3516,6 +3516,7 @@ apply_wqattrs_prepare(struct workqueue_struct *wq, { struct apply_wqattrs_ctx *ctx; struct workqueue_attrs *new_attrs, *tmp_attrs; + struct pool_workqueue *pwq; int node; lockdep_assert_held(&wq_pool_mutex); @@ -3556,9 +3557,16 @@ apply_wqattrs_prepare(struct workqueue_struct *wq, for_each_node(node) { if (wq_calc_node_cpumask(new_attrs, node, -1, tmp_attrs->cpumask)) { - ctx->pwq_tbl[node] = alloc_unbound_pwq(wq, tmp_attrs); - if (!ctx->pwq_tbl[node]) - goto out_free; + /* Try to reuse the current one */ + pwq = unbound_pwq_by_node(wq, node); + if (pwq && wqattrs_equal(tmp_attrs, pwq->pool->attrs)) { + get_pwq_unlocked(pwq); + } else { + pwq = alloc_unbound_pwq(wq, tmp_attrs); + if (!pwq) + goto out_free; + } + ctx->pwq_tbl[node] = pwq; } else { ctx->dfl_pwq->refcnt++; ctx->pwq_tbl[node] = ctx->dfl_pwq; @@ -3717,7 +3725,6 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu, cpumask = target_attrs->cpumask; copy_workqueue_attrs(target_attrs, wq->unbound_attrs); - pwq = unbound_pwq_by_node(wq, node); /* * Let's determine what needs to be done. If the target cpumask is @@ -3726,6 +3733,7 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu, * equals the default pwq's, the default pwq should be used. */ if (wq_calc_node_cpumask(wq->dfl_pwq->pool->attrs, node, cpu_off, cpumask)) { + pwq = unbound_pwq_by_node(wq, node); if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask)) return; } else { -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/