From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dongli Zhang <dongli.zhang@oracle.com>
Subject: Re: virtio-blk: should num_vqs be limited by num_possible_cpus()?
Date: Thu, 21 Mar 2019 10:14:38 +0800
Message-ID: <92cd9e4b-5a40-5c8c-14a6-0787c94c5dbf@oracle.com>
References: <e4afe4c5-0262-4500-aeec-60f30734b4fc@default>
	<20190312183351.74764f4f.cohuck@redhat.com>
	<173d19c9-24db-35f2-269f-0b9b83bd0ad6@oracle.com>
	<20190313103900.1ea7f996.cohuck@redhat.com>
	<a3f24cfa-5160-0ccc-decc-a48362c8de19@oracle.com>
	<537e6420-8994-43d6-1d4d-ccb6e0fafa0b@redhat.com>
	<20190315134112.7d63348c.cohuck@redhat.com>
	<1df52766-88fb-6b23-d160-b891c3017133@redhat.com>
	<0fbdcfa6-cbd7-4f09-93b1-40898d5f77d1@oracle.com>
	<f92a5ef9-04b9-d6fa-a7f8-c855a87cd0fb@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
Return-path: <virtualization-bounces@lists.linux-foundation.org>
In-Reply-To: <f92a5ef9-04b9-d6fa-a7f8-c855a87cd0fb@redhat.com>
Content-Language: en-US
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/virtualization>,
	<mailto:virtualization-request@lists.linux-foundation.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/virtualization/>
List-Post: <mailto:virtualization@lists.linux-foundation.org>
List-Help: <mailto:virtualization-request@lists.linux-foundation.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/virtualization>,
	<mailto:virtualization-request@lists.linux-foundation.org?subject=subscribe>
Sender: virtualization-bounces@lists.linux-foundation.org
Errors-To: virtualization-bounces@lists.linux-foundation.org
To: Jason Wang <jasowang@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>
Cc: axboe@kernel.dk, mst@redhat.com, Cornelia Huck <cohuck@redhat.com>, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-block@vger.kernel.org
List-Id: virtualization@lists.linuxfoundation.org
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