From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752633AbbIOXK5 (ORCPT ); Tue, 15 Sep 2015 19:10:57 -0400 Received: from p3plsmtps2ded01.prod.phx3.secureserver.net ([208.109.80.58]:47873 "EHLO p3plsmtps2ded01.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752408AbbIOXKD (ORCPT ); Tue, 15 Sep 2015 19:10:03 -0400 x-originating-ip: 72.167.245.219 From: "K. Y. Srinivasan" To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, vkuznets@redhat.com, jasowang@redhat.com Cc: Dexuan Cui , "K. Y. Srinivasan" Subject: [PATCH 1/5] Drivers: hv: vmbus: fix init_vp_index() for reloading hv_netvsc Date: Tue, 15 Sep 2015 17:37:50 -0700 Message-Id: <1442363874-22508-1-git-send-email-kys@microsoft.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1442363823-22428-1-git-send-email-kys@microsoft.com> References: <1442363823-22428-1-git-send-email-kys@microsoft.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dexuan Cui This fixes the recent commit 3b71107d73b16074afa7658f3f0fcf837aabfe24: Drivers: hv: vmbus: Further improve CPU affiliation logic Without the fix, reloading hv_netvsc hangs the guest. Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan --- drivers/hv/channel_mgmt.c | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-) diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 3ab4753..8a4105c 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -204,6 +204,8 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid) spin_lock_irqsave(&vmbus_connection.channel_lock, flags); list_del(&channel->listentry); spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); + + primary_channel = channel; } else { primary_channel = channel->primary_channel; spin_lock_irqsave(&primary_channel->lock, flags); @@ -211,6 +213,14 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid) primary_channel->num_sc--; spin_unlock_irqrestore(&primary_channel->lock, flags); } + + /* + * We need to free the bit for init_vp_index() to work in the case + * of sub-channel, when we reload drivers like hv_netvsc. + */ + cpumask_clear_cpu(channel->target_cpu, + &primary_channel->alloced_cpus_in_node); + free_channel(channel); } @@ -457,6 +467,13 @@ static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_gui continue; } + /* + * NOTE: in the case of sub-channel, we clear the sub-channel + * related bit(s) in primary->alloced_cpus_in_node in + * hv_process_channel_removal(), so when we reload drivers + * like hv_netvsc in SMP guest, here we're able to re-allocate + * bit from primary->alloced_cpus_in_node. + */ if (!cpumask_test_cpu(cur_cpu, &primary->alloced_cpus_in_node)) { cpumask_set_cpu(cur_cpu, -- 1.7.4.1