From: Paolo Bonzini <pbonzini@redhat.com>
To: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>,
kvm-devel <kvm@vger.kernel.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jan Kiszka <jan.kiszka@siemens.com>,
qemu-devel <qemu-devel@nongnu.org>,
lf-virt <virtualization@lists.linux-foundation.org>,
Anthony Liguori <aliguori@linux.vnet.ibm.com>,
target-devel <target-devel@vger.kernel.org>,
Hannes Reinecke <hare@suse.de>, Asias He <asias@redhat.com>,
Zhi Yong Wu <wuzhy@cn.ibm.com>, Christoph Hellwig <hch@lst.de>
Subject: Re: [Qemu-devel] [PATCH 0/5] vhost-scsi: Add support for host virtualized target
Date: Fri, 14 Sep 2012 10:21:05 +0200 [thread overview]
Message-ID: <5052E8F1.8060401@redhat.com> (raw)
In-Reply-To: <1347567129.7359.14.camel@haakon2.linux-iscsi.org>
Il 13/09/2012 22:12, Nicholas A. Bellinger ha scritto:
>> > Are you still seeing the performance degradation discussed in the thread
>> >
>> > "vhost-scsi port to v1.1.0 + MSI-X performance regression"
>> >
> So the performance regression reported here with QEMU v1.2-rc +
> virtio-scsi ended up being related to virtio interrupts being delivered
> across multiple CPUs.
>
> After explicitly setting the IRQ affinity of the virtio0-request MSI-X
> vector to a specific CPU, the small block (4k) mixed random I/O
> performance jumped back up to the expected ~100K IOPs for a single LUN.
Have you tried setting rq_affinity to 2? Benchmarking this against
multiqueue virtio-scsi is on my todo list.
Paolo
> FYI, I just tried this again with the most recent QEMU v1.2.50 (v1.3-rc)
> code, and both cases appear to be performing as expected once again
> regardless of the explicit IRQ affinity setting.
next prev parent reply other threads:[~2012-09-14 8:21 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-07 6:48 [Qemu-devel] [PATCH 0/5] vhost-scsi: Add support for host virtualized target Nicholas A. Bellinger
2012-09-07 6:48 ` [Qemu-devel] [PATCH 1/5] monitor: Rename+move net_handle_fd_param -> monitor_handle_fd_param Nicholas A. Bellinger
2012-09-07 6:48 ` [Qemu-devel] [PATCH 2/5] vhost: Pass device path to vhost_dev_init() Nicholas A. Bellinger
2012-09-07 6:48 ` [Qemu-devel] [PATCH 3/5] vhost-scsi: add -vhost-scsi host device for use with tcm-vhost Nicholas A. Bellinger
2012-09-07 6:48 ` [Qemu-devel] [PATCH 4/5] virtio-scsi: Add start/stop functionality for vhost-scsi Nicholas A. Bellinger
2012-09-07 16:00 ` Paolo Bonzini
2012-09-07 19:23 ` Nicholas A. Bellinger
2012-09-07 20:30 ` Paolo Bonzini
2012-09-08 22:40 ` Michael S. Tsirkin
2012-09-10 6:16 ` Paolo Bonzini
2012-09-10 6:24 ` Michael S. Tsirkin
2012-09-10 6:42 ` Paolo Bonzini
2012-09-10 6:49 ` Michael S. Tsirkin
2012-09-11 13:46 ` Anthony Liguori
2012-09-11 15:07 ` Michael S. Tsirkin
2012-09-13 22:27 ` Nicholas A. Bellinger
2012-09-14 6:45 ` Paolo Bonzini
2012-09-14 12:34 ` Michael S. Tsirkin
2012-09-14 12:50 ` Michael S. Tsirkin
2012-09-07 6:48 ` [Qemu-devel] [PATCH 5/5] virtio-scsi: Set max_target=0 during vhost-scsi operation Nicholas A. Bellinger
2012-09-11 4:36 ` [Qemu-devel] [PATCH 0/5] vhost-scsi: Add support for host virtualized target Asias He
2012-09-13 20:12 ` Nicholas A. Bellinger
2012-09-14 8:21 ` Paolo Bonzini [this message]
2013-01-17 16:43 ` Michael S. Tsirkin
2013-01-17 21:07 ` Nicholas A. Bellinger
2013-01-21 8:50 ` Michael S. Tsirkin
2013-04-02 3:28 ` Wenchao Xia
2013-04-02 5:07 ` Nicholas A. Bellinger
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