From: Rusty Russell <rusty@rustcorp.com.au>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [RFC] virtio: use mandatory barriers for remote processor vdevs
Date: Fri, 02 Dec 2011 10:56:33 +1030 [thread overview]
Message-ID: <8762hzsts6.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20111201081236.GB5479@redhat.com>
On Thu, 1 Dec 2011 10:12:37 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Thu, Dec 01, 2011 at 12:58:59PM +1030, Rusty Russell wrote:
> > On Thu, 1 Dec 2011 01:13:07 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > > For x86, stores into memory are ordered. So I think that yes, smp_XXX
> > > can be selected at compile time.
> > >
> > > So let's forget the virtio strangeness for a minute,
> >
> > Hmm, we got away with light barriers because we knew we were not
> > *really* talking to a device. But now with virtio-mmio, turns out we
> > are :)
>
> You think virtio-mmio this issue too? It's reported on remoteproc...
I think any non-virtual, non-PCI device has to worry about it. Perhaps
all virtio-mmio are virtual (at this point).
I'm tempted to say we want permission from the device to do relaxed
barriers (so I don't have to worry about it!)
> > I'm really tempted to revert d57ed95 for 3.2, and we can revisit this
> > optimization later if it proves worthwhile.
>
> Generally it does seem the best we can do for 3.2.
>
> Given it's rc3, I'd be a bit wary of introducing regressions - I'll try
> to find some real setups (as in - not my laptop) to run some benchmarks
> on, to verify there's no major problem.
> I hope I can report on this in about a week from now - want to hold onto this meanwhile?
Yep, no huge hurry. Thanks!
Cheers,
Rusty.
WARNING: multiple messages have this Message-ID (diff)
From: rusty@rustcorp.com.au (Rusty Russell)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] virtio: use mandatory barriers for remote processor vdevs
Date: Fri, 02 Dec 2011 10:56:33 +1030 [thread overview]
Message-ID: <8762hzsts6.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20111201081236.GB5479@redhat.com>
On Thu, 1 Dec 2011 10:12:37 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Thu, Dec 01, 2011 at 12:58:59PM +1030, Rusty Russell wrote:
> > On Thu, 1 Dec 2011 01:13:07 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > > For x86, stores into memory are ordered. So I think that yes, smp_XXX
> > > can be selected at compile time.
> > >
> > > So let's forget the virtio strangeness for a minute,
> >
> > Hmm, we got away with light barriers because we knew we were not
> > *really* talking to a device. But now with virtio-mmio, turns out we
> > are :)
>
> You think virtio-mmio this issue too? It's reported on remoteproc...
I think any non-virtual, non-PCI device has to worry about it. Perhaps
all virtio-mmio are virtual (at this point).
I'm tempted to say we want permission from the device to do relaxed
barriers (so I don't have to worry about it!)
> > I'm really tempted to revert d57ed95 for 3.2, and we can revisit this
> > optimization later if it proves worthwhile.
>
> Generally it does seem the best we can do for 3.2.
>
> Given it's rc3, I'd be a bit wary of introducing regressions - I'll try
> to find some real setups (as in - not my laptop) to run some benchmarks
> on, to verify there's no major problem.
> I hope I can report on this in about a week from now - want to hold onto this meanwhile?
Yep, no huge hurry. Thanks!
Cheers,
Rusty.
WARNING: multiple messages have this Message-ID (diff)
From: Rusty Russell <rusty@rustcorp.com.au>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>,
virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC] virtio: use mandatory barriers for remote processor vdevs
Date: Fri, 02 Dec 2011 10:56:33 +1030 [thread overview]
Message-ID: <8762hzsts6.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20111201081236.GB5479@redhat.com>
On Thu, 1 Dec 2011 10:12:37 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Thu, Dec 01, 2011 at 12:58:59PM +1030, Rusty Russell wrote:
> > On Thu, 1 Dec 2011 01:13:07 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > > For x86, stores into memory are ordered. So I think that yes, smp_XXX
> > > can be selected at compile time.
> > >
> > > So let's forget the virtio strangeness for a minute,
> >
> > Hmm, we got away with light barriers because we knew we were not
> > *really* talking to a device. But now with virtio-mmio, turns out we
> > are :)
>
> You think virtio-mmio this issue too? It's reported on remoteproc...
I think any non-virtual, non-PCI device has to worry about it. Perhaps
all virtio-mmio are virtual (at this point).
I'm tempted to say we want permission from the device to do relaxed
barriers (so I don't have to worry about it!)
> > I'm really tempted to revert d57ed95 for 3.2, and we can revisit this
> > optimization later if it proves worthwhile.
>
> Generally it does seem the best we can do for 3.2.
>
> Given it's rc3, I'd be a bit wary of introducing regressions - I'll try
> to find some real setups (as in - not my laptop) to run some benchmarks
> on, to verify there's no major problem.
> I hope I can report on this in about a week from now - want to hold onto this meanwhile?
Yep, no huge hurry. Thanks!
Cheers,
Rusty.
next prev parent reply other threads:[~2011-12-02 0:26 UTC|newest]
Thread overview: 111+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-29 12:31 [RFC] virtio: use mandatory barriers for remote processor vdevs Ohad Ben-Cohen
2011-11-29 12:31 ` Ohad Ben-Cohen
2011-11-29 13:11 ` Michael S. Tsirkin
2011-11-29 13:11 ` Michael S. Tsirkin
2011-11-29 13:11 ` Michael S. Tsirkin
2011-11-29 13:57 ` Ohad Ben-Cohen
2011-11-29 13:57 ` Ohad Ben-Cohen
2011-11-29 13:57 ` Ohad Ben-Cohen
2011-11-29 15:16 ` Michael S. Tsirkin
2011-11-29 15:16 ` Michael S. Tsirkin
2011-11-29 15:16 ` Michael S. Tsirkin
2011-11-30 11:45 ` Ohad Ben-Cohen
2011-11-30 11:45 ` Ohad Ben-Cohen
2011-11-30 11:45 ` Ohad Ben-Cohen
2011-11-30 14:59 ` Michael S. Tsirkin
2011-11-30 14:59 ` Michael S. Tsirkin
2011-11-30 14:59 ` Michael S. Tsirkin
2011-11-30 16:04 ` Ohad Ben-Cohen
2011-11-30 16:04 ` Ohad Ben-Cohen
2011-11-30 16:15 ` Michael S. Tsirkin
2011-11-30 16:15 ` Michael S. Tsirkin
2011-11-30 16:15 ` Michael S. Tsirkin
2011-11-30 16:24 ` Ohad Ben-Cohen
2011-11-30 16:24 ` Ohad Ben-Cohen
2011-11-30 16:24 ` Ohad Ben-Cohen
2011-11-30 23:27 ` Ohad Ben-Cohen
2011-11-30 23:27 ` Ohad Ben-Cohen
2011-11-30 23:27 ` Ohad Ben-Cohen
2011-11-30 23:43 ` Michael S. Tsirkin
2011-11-30 23:43 ` Michael S. Tsirkin
2011-11-30 23:43 ` Michael S. Tsirkin
2011-12-01 6:20 ` Ohad Ben-Cohen
2011-12-01 6:20 ` Ohad Ben-Cohen
2011-12-01 6:20 ` Ohad Ben-Cohen
2011-11-30 16:04 ` Ohad Ben-Cohen
2011-11-29 15:19 ` Michael S. Tsirkin
2011-11-29 15:19 ` Michael S. Tsirkin
2011-11-29 15:19 ` Michael S. Tsirkin
2011-11-30 11:55 ` Ohad Ben-Cohen
2011-11-30 11:55 ` Ohad Ben-Cohen
2011-11-30 11:55 ` Ohad Ben-Cohen
2011-11-30 14:50 ` Michael S. Tsirkin
2011-11-30 14:50 ` Michael S. Tsirkin
2011-11-30 14:50 ` Michael S. Tsirkin
2011-11-30 22:43 ` Ohad Ben-Cohen
2011-11-30 22:43 ` Ohad Ben-Cohen
2011-11-30 22:43 ` Ohad Ben-Cohen
2011-11-30 23:13 ` Michael S. Tsirkin
2011-11-30 23:13 ` Michael S. Tsirkin
2011-11-30 23:13 ` Michael S. Tsirkin
2011-12-01 2:28 ` Rusty Russell
2011-12-01 2:28 ` Rusty Russell
2011-12-01 2:28 ` Rusty Russell
2011-12-01 7:15 ` Ohad Ben-Cohen
2011-12-01 7:15 ` Ohad Ben-Cohen
2011-12-01 7:15 ` Ohad Ben-Cohen
2011-12-01 8:12 ` Michael S. Tsirkin
2011-12-01 8:12 ` Michael S. Tsirkin
2011-12-01 8:12 ` Michael S. Tsirkin
2011-12-02 0:26 ` Rusty Russell [this message]
2011-12-02 0:26 ` Rusty Russell
2011-12-02 0:26 ` Rusty Russell
2011-12-01 6:14 ` Ohad Ben-Cohen
2011-12-01 6:14 ` Ohad Ben-Cohen
2011-12-01 6:14 ` Ohad Ben-Cohen
2011-12-01 9:09 ` Michael S. Tsirkin
2011-12-01 9:09 ` Michael S. Tsirkin
2011-12-01 9:09 ` Michael S. Tsirkin
2011-12-02 23:09 ` Benjamin Herrenschmidt
2011-12-02 23:09 ` Benjamin Herrenschmidt
2011-12-02 23:09 ` Benjamin Herrenschmidt
2011-12-03 5:14 ` Rusty Russell
2011-12-03 5:14 ` Rusty Russell
2011-12-03 5:14 ` Rusty Russell
2011-12-11 12:25 ` Michael S. Tsirkin
2011-12-11 12:25 ` Michael S. Tsirkin
2011-12-11 12:25 ` Michael S. Tsirkin
2011-12-11 22:27 ` Benjamin Herrenschmidt
2011-12-11 22:27 ` Benjamin Herrenschmidt
2011-12-11 22:27 ` Benjamin Herrenschmidt
2011-12-12 3:06 ` Amos Kong
2011-12-12 3:06 ` Amos Kong
2011-12-12 3:06 ` Amos Kong
2011-12-12 5:12 ` Rusty Russell
2011-12-12 5:12 ` Rusty Russell
2011-12-12 5:12 ` Rusty Russell
2011-12-12 23:56 ` Amos Kong
2011-12-12 23:56 ` Amos Kong
2011-12-12 23:56 ` Amos Kong
2011-12-19 2:35 ` Rusty Russell
2011-12-19 2:35 ` Rusty Russell
2011-12-19 2:35 ` Rusty Russell
2011-12-19 2:19 ` Amos Kong
2011-12-19 2:19 ` Amos Kong
2011-12-19 2:19 ` Amos Kong
2011-12-19 2:41 ` Benjamin Herrenschmidt
2011-12-19 2:41 ` Benjamin Herrenschmidt
2011-12-19 2:41 ` Benjamin Herrenschmidt
2011-12-19 7:21 ` Amos Kong
2011-12-19 7:21 ` Amos Kong
2011-12-19 7:21 ` Amos Kong
2011-12-19 2:50 ` Amos Kong
2011-12-19 2:50 ` Amos Kong
2011-12-19 2:50 ` Amos Kong
2011-12-19 8:37 ` Rusty Russell
2011-12-19 8:37 ` Rusty Russell
2011-12-19 8:37 ` Rusty Russell
2011-12-03 6:01 ` Ohad Ben-Cohen
2011-12-03 6:01 ` Ohad Ben-Cohen
2011-12-03 6:01 ` Ohad Ben-Cohen
-- strict thread matches above, loose matches on Subject: below --
2011-11-29 12:31 Ohad Ben-Cohen
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