From: "Michael S. Tsirkin" <mst@redhat.com>
To: Stefan Hajnoczi <stefanha@redhat.com>
Cc: fam@euphon.net, linux-scsi@vger.kernel.org,
qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org,
target-devel@vger.kernel.org, pbonzini@redhat.com,
Mike Christie <michael.christie@oracle.com>
Subject: Re: [PATCH 00/10] vhost/qemu: thread per IO SCSI vq
Date: Thu, 19 Nov 2020 09:46:26 -0500 [thread overview]
Message-ID: <20201119094315-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20201118113117.GF182763@stefanha-x1.localdomain>
On Wed, Nov 18, 2020 at 11:31:17AM +0000, Stefan Hajnoczi wrote:
> > My preference has been:
> >
> > 1. If we were to ditch cgroups, then add a new interface that would allow
> > us to bind threads to a specific CPU, so that it lines up with the guest's
> > mq to CPU mapping.
>
> A 1:1 vCPU/vq->CPU mapping isn't desirable in all cases.
>
> The CPU affinity is a userspace policy decision. The host kernel should
> provide a mechanism but not the policy. That way userspace can decide
> which workers are shared by multiple vqs and on which physical CPUs they
> should run.
So if we let userspace dictate the threading policy then I think binding
vqs to userspace threads and running there makes the most sense,
no need to create the threads.
--
MST
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next prev parent reply other threads:[~2020-11-19 14:46 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1605223150-10888-1-git-send-email-michael.christie@oracle.com>
[not found] ` <1605223150-10888-3-git-send-email-michael.christie@oracle.com>
2020-11-17 13:04 ` [PATCH 01/10] vhost: remove work arg from vhost_work_flush Stefan Hajnoczi
[not found] ` <1605223150-10888-4-git-send-email-michael.christie@oracle.com>
2020-11-17 13:07 ` [PATCH 02/10] vhost scsi: remove extra flushes Stefan Hajnoczi
[not found] ` <1605223150-10888-5-git-send-email-michael.christie@oracle.com>
2020-11-17 13:07 ` [PATCH 03/10] vhost poll: fix coding style Stefan Hajnoczi
[not found] ` <1605223150-10888-7-git-send-email-michael.christie@oracle.com>
2020-11-17 15:32 ` [PATCH 05/10] vhost: poll support support multiple workers Stefan Hajnoczi
[not found] ` <1605223150-10888-8-git-send-email-michael.christie@oracle.com>
2020-11-17 16:04 ` [PATCH 06/10] vhost scsi: make SCSI cmd completion per vq Stefan Hajnoczi
[not found] ` <1605223150-10888-9-git-send-email-michael.christie@oracle.com>
2020-11-17 16:05 ` [PATCH 07/10] vhost, vhost-scsi: flush IO vqs then send TMF rsp Stefan Hajnoczi
[not found] ` <1605223150-10888-10-git-send-email-michael.christie@oracle.com>
2020-11-17 16:08 ` [PATCH 08/10] vhost: move msg_handler to new ops struct Stefan Hajnoczi
[not found] ` <1605223150-10888-11-git-send-email-michael.christie@oracle.com>
2020-11-17 16:14 ` [PATCH 09/10] vhost: add VHOST_SET_VRING_ENABLE support Stefan Hajnoczi
2020-11-17 16:40 ` [PATCH 00/10] vhost/qemu: thread per IO SCSI vq Stefan Hajnoczi
2020-11-18 5:17 ` Jason Wang
[not found] ` <8318de9f-c585-39f8-d931-1ff5e0341d75@oracle.com>
2020-11-18 7:54 ` Jason Wang
[not found] ` <d6ffcf17-ab12-4830-cc3c-0f0402fb8a0f@oracle.com>
2020-11-19 4:35 ` Jason Wang
[not found] ` <b3343762-bb11-b750-46ec-43b5556f2b8e@oracle.com>
2020-11-18 9:54 ` Michael S. Tsirkin
2020-11-19 14:00 ` Stefan Hajnoczi
2020-11-18 11:31 ` Stefan Hajnoczi
2020-11-19 14:46 ` Michael S. Tsirkin [this message]
[not found] ` <ceebdc90-3ffc-1563-ff85-12a848bcba18@oracle.com>
2020-11-19 16:24 ` Stefan Hajnoczi
[not found] ` <ffd88f0c-981e-a102-4b08-f29d6b9a0f71@oracle.com>
2020-11-19 17:08 ` Stefan Hajnoczi
2020-11-20 8:45 ` Stefan Hajnoczi
2020-11-20 12:31 ` Michael S. Tsirkin
2020-12-01 12:59 ` Stefan Hajnoczi
2020-12-01 13:45 ` Stefano Garzarella
2020-12-01 17:43 ` Stefan Hajnoczi
2020-12-02 10:35 ` Stefano Garzarella
2020-11-23 15:17 ` Stefano Garzarella
[not found] ` <1605223150-10888-2-git-send-email-michael.christie@oracle.com>
2020-11-17 11:53 ` [PATCH 1/1] qemu vhost scsi: add VHOST_SET_VRING_ENABLE support Stefan Hajnoczi
2020-12-02 9:59 ` Michael S. Tsirkin
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