From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F696C433FF for ; Wed, 7 Aug 2019 20:10:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D96921922 for ; Wed, 7 Aug 2019 20:10:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389277AbfHGUK5 (ORCPT ); Wed, 7 Aug 2019 16:10:57 -0400 Received: from mga12.intel.com ([192.55.52.136]:16763 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730180AbfHGUK4 (ORCPT ); Wed, 7 Aug 2019 16:10:56 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Aug 2019 13:10:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,358,1559545200"; d="scan'208";a="165457363" Received: from jderrick-mobl.amr.corp.intel.com ([10.232.115.152]) by orsmga007.jf.intel.com with ESMTP; 07 Aug 2019 13:10:55 -0700 From: Jon Derrick To: Thomas Gleixner , Cc: , Jon Derrick Subject: [PATCH] genirq/affinity: report extra vectors on uneven nodes Date: Wed, 7 Aug 2019 14:10:51 -0600 Message-Id: <20190807201051.32662-1-jonathan.derrick@intel.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current irq spreading algorithm spreads vectors amongst cpus evenly per node. If a node has more cpus than another node, the extra vectors being spread may not be reported back to the caller. This is most apparent with the NVMe driver and nr_cpus < vectors, where the underreporting results in the caller's WARN being triggered: irq_build_affinity_masks() ... if (nr_present < numvecs) WARN_ON(nr_present + nr_others < numvecs); Signed-off-by: Jon Derrick --- kernel/irq/affinity.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c index 4352b08ae48d..9beafb8c7e92 100644 --- a/kernel/irq/affinity.c +++ b/kernel/irq/affinity.c @@ -127,7 +127,8 @@ static int __irq_build_affinity_masks(unsigned int startvec, } for_each_node_mask(n, nodemsk) { - unsigned int ncpus, v, vecs_to_assign, vecs_per_node; + unsigned int ncpus, v, vecs_to_assign, total_vecs_to_assign, + vecs_per_node; /* Spread the vectors per node */ vecs_per_node = (numvecs - (curvec - firstvec)) / nodes; @@ -141,14 +142,16 @@ static int __irq_build_affinity_masks(unsigned int startvec, /* Account for rounding errors */ extra_vecs = ncpus - vecs_to_assign * (ncpus / vecs_to_assign); + total_vecs_to_assign = vecs_to_assign + extra_vecs; - for (v = 0; curvec < last_affv && v < vecs_to_assign; + for (v = 0; curvec < last_affv && v < total_vecs_to_assign; curvec++, v++) { cpus_per_vec = ncpus / vecs_to_assign; /* Account for extra vectors to compensate rounding errors */ if (extra_vecs) { cpus_per_vec++; + v++; --extra_vecs; } irq_spread_init_one(&masks[curvec].mask, nmsk, -- 2.20.1