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From: Rusty Russell <rusty@rustcorp.com.au>
To: "Michael S. Tsirkin" <mst@redhat.com>, Ohad Ben-Cohen <ohad@wizery.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: Thu, 01 Dec 2011 12:58:59 +1030	[thread overview]
Message-ID: <87zkfdrpn8.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20111130231306.GD30031@redhat.com>

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 :)

I'm really tempted to revert d57ed95 for 3.2, and we can revisit this
optimization later if it proves worthwhile.

Thoughts?
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: Thu, 01 Dec 2011 12:58:59 +1030	[thread overview]
Message-ID: <87zkfdrpn8.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20111130231306.GD30031@redhat.com>

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 :)

I'm really tempted to revert d57ed95 for 3.2, and we can revisit this
optimization later if it proves worthwhile.

Thoughts?
Rusty. 

WARNING: multiple messages have this Message-ID (diff)
From: Rusty Russell <rusty@rustcorp.com.au>
To: "Michael S. Tsirkin" <mst@redhat.com>, Ohad Ben-Cohen <ohad@wizery.com>
Cc: 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: Thu, 01 Dec 2011 12:58:59 +1030	[thread overview]
Message-ID: <87zkfdrpn8.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20111130231306.GD30031@redhat.com>

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 :)

I'm really tempted to revert d57ed95 for 3.2, and we can revisit this
optimization later if it proves worthwhile.

Thoughts?
Rusty. 

  reply	other threads:[~2011-12-01  2:28 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 16:04             ` 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
2011-11-29 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 [this message]
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
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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