From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754307AbbKLKl2 (ORCPT ); Thu, 12 Nov 2015 05:41:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59864 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752696AbbKLKl1 (ORCPT ); Thu, 12 Nov 2015 05:41:27 -0500 From: Vitaly Kuznetsov To: Dexuan Cui Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, "K. Y. Srinivasan" Subject: Re: [PATCH V2 10/12] Drivers: hv: vmbus: channge vmbus_connection.channel_lock to mutex References: <1447295158-9012-1-git-send-email-kys@microsoft.com> <1447295184-9051-1-git-send-email-kys@microsoft.com> <1447295184-9051-10-git-send-email-kys@microsoft.com> Date: Thu, 12 Nov 2015 11:41:22 +0100 In-Reply-To: <1447295184-9051-10-git-send-email-kys@microsoft.com> (K. Y. Srinivasan's message of "Wed, 11 Nov 2015 18:26:22 -0800") Message-ID: <87vb97ijot.fsf@vitty.brq.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "K. Y. Srinivasan" writes: > From: Dexuan Cui > > spinlock is unnecessary here. > mutex is enough. Hm, mutex is usually required when we need to sleep and a spinlock is enough otherwise :-) Or are you trying to say we don't need to disable interrupts here? In that can maybe we can just switch to spin_lock()/spin_unlock()? > > Signed-off-by: Dexuan Cui > Signed-off-by: K. Y. Srinivasan > --- > drivers/hv/channel_mgmt.c | 12 ++++++------ > drivers/hv/connection.c | 7 +++---- > drivers/hv/hyperv_vmbus.h | 2 +- > 3 files changed, 10 insertions(+), 11 deletions(-) > > diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c > index 9c9da3a..d013171 100644 > --- a/drivers/hv/channel_mgmt.c > +++ b/drivers/hv/channel_mgmt.c > @@ -206,9 +206,9 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid) > } > > if (channel->primary_channel == NULL) { > - spin_lock_irqsave(&vmbus_connection.channel_lock, flags); > + mutex_lock(&vmbus_connection.channel_mutex); > list_del(&channel->listentry); > - spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); > + mutex_unlock(&vmbus_connection.channel_mutex); > > primary_channel = channel; > } else { > @@ -253,7 +253,7 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) > unsigned long flags; > > /* Make sure this is a new offer */ > - spin_lock_irqsave(&vmbus_connection.channel_lock, flags); > + mutex_lock(&vmbus_connection.channel_mutex); > > list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { > if (!uuid_le_cmp(channel->offermsg.offer.if_type, > @@ -269,7 +269,7 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) > list_add_tail(&newchannel->listentry, > &vmbus_connection.chn_list); > > - spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); > + mutex_unlock(&vmbus_connection.channel_mutex); > > if (!fnew) { > /* > @@ -341,9 +341,9 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) > err_deq_chan: > vmbus_release_relid(newchannel->offermsg.child_relid); > > - spin_lock_irqsave(&vmbus_connection.channel_lock, flags); > + mutex_lock(&vmbus_connection.channel_mutex); > list_del(&newchannel->listentry); > - spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); > + mutex_unlock(&vmbus_connection.channel_mutex); > > if (newchannel->target_cpu != get_cpu()) { > put_cpu(); > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c > index 4fc2e88..521f48e 100644 > --- a/drivers/hv/connection.c > +++ b/drivers/hv/connection.c > @@ -146,7 +146,7 @@ int vmbus_connect(void) > spin_lock_init(&vmbus_connection.channelmsg_lock); > > INIT_LIST_HEAD(&vmbus_connection.chn_list); > - spin_lock_init(&vmbus_connection.channel_lock); > + mutex_init(&vmbus_connection.channel_mutex); > > /* > * Setup the vmbus event connection for channel interrupt > @@ -282,11 +282,10 @@ struct vmbus_channel *relid2channel(u32 relid) > { > struct vmbus_channel *channel; > struct vmbus_channel *found_channel = NULL; > - unsigned long flags; > struct list_head *cur, *tmp; > struct vmbus_channel *cur_sc; > > - spin_lock_irqsave(&vmbus_connection.channel_lock, flags); > + mutex_lock(&vmbus_connection.channel_mutex); > list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { > if (channel->offermsg.child_relid == relid) { > found_channel = channel; > @@ -305,7 +304,7 @@ struct vmbus_channel *relid2channel(u32 relid) > } > } > } > - spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); > + mutex_unlock(&vmbus_connection.channel_mutex); > > return found_channel; > } > diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h > index 64950d8..0af6dce 100644 > --- a/drivers/hv/hyperv_vmbus.h > +++ b/drivers/hv/hyperv_vmbus.h > @@ -688,7 +688,7 @@ struct vmbus_connection { > > /* List of channels */ > struct list_head chn_list; > - spinlock_t channel_lock; > + struct mutex channel_mutex; > > struct workqueue_struct *work_queue; > }; -- Vitaly