From: "Michael S. Tsirkin" <mst@redhat.com>
To: Rafael Aquini <aquini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org, linux-mm@kvack.org,
Andi Kleen <andi@firstfloor.org>,
Minchan Kim <minchan@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: Re: [PATCH v8 1/5] mm: introduce a common interface for balloon pages mobility
Date: Tue, 21 Aug 2012 22:30:31 +0300 [thread overview]
Message-ID: <20120821193031.GC9027@redhat.com> (raw)
In-Reply-To: <20120821192357.GD12294@t510.redhat.com>
On Tue, Aug 21, 2012 at 04:23:58PM -0300, Rafael Aquini wrote:
> On Tue, Aug 21, 2012 at 10:13:30PM +0300, Michael S. Tsirkin wrote:
> > >
> > > I believe rcu_dereference_protected() is what I want/need here, since this code
> > > is always called for pages which we hold locked (PG_locked bit).
> >
> > It would only help if we locked the page while updating the mapping,
> > as far as I can see we don't.
> >
>
> But we can do it. In fact, by doing it (locking the page) we can easily avoid
> the nasty race balloon_isolate_page / leak_balloon, in a much simpler way, IMHO.
Absolutely. Further, we should look hard at whether most RCU uses
in this patchset can be replaced with page lock.
--
MST
WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Rafael Aquini <aquini@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Rusty Russell <rusty@rustcorp.com.au>,
Rik van Riel <riel@redhat.com>, Mel Gorman <mel@csn.ul.ie>,
Andi Kleen <andi@firstfloor.org>,
Andrew Morton <akpm@linux-foundation.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Minchan Kim <minchan@kernel.org>
Subject: Re: [PATCH v8 1/5] mm: introduce a common interface for balloon pages mobility
Date: Tue, 21 Aug 2012 22:30:31 +0300 [thread overview]
Message-ID: <20120821193031.GC9027@redhat.com> (raw)
In-Reply-To: <20120821192357.GD12294@t510.redhat.com>
On Tue, Aug 21, 2012 at 04:23:58PM -0300, Rafael Aquini wrote:
> On Tue, Aug 21, 2012 at 10:13:30PM +0300, Michael S. Tsirkin wrote:
> > >
> > > I believe rcu_dereference_protected() is what I want/need here, since this code
> > > is always called for pages which we hold locked (PG_locked bit).
> >
> > It would only help if we locked the page while updating the mapping,
> > as far as I can see we don't.
> >
>
> But we can do it. In fact, by doing it (locking the page) we can easily avoid
> the nasty race balloon_isolate_page / leak_balloon, in a much simpler way, IMHO.
Absolutely. Further, we should look hard at whether most RCU uses
in this patchset can be replaced with page lock.
--
MST
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WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Rafael Aquini <aquini@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Rusty Russell <rusty@rustcorp.com.au>,
Rik van Riel <riel@redhat.com>, Mel Gorman <mel@csn.ul.ie>,
Andi Kleen <andi@firstfloor.org>,
Andrew Morton <akpm@linux-foundation.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Minchan Kim <minchan@kernel.org>
Subject: Re: [PATCH v8 1/5] mm: introduce a common interface for balloon pages mobility
Date: Tue, 21 Aug 2012 22:30:31 +0300 [thread overview]
Message-ID: <20120821193031.GC9027@redhat.com> (raw)
In-Reply-To: <20120821192357.GD12294@t510.redhat.com>
On Tue, Aug 21, 2012 at 04:23:58PM -0300, Rafael Aquini wrote:
> On Tue, Aug 21, 2012 at 10:13:30PM +0300, Michael S. Tsirkin wrote:
> > >
> > > I believe rcu_dereference_protected() is what I want/need here, since this code
> > > is always called for pages which we hold locked (PG_locked bit).
> >
> > It would only help if we locked the page while updating the mapping,
> > as far as I can see we don't.
> >
>
> But we can do it. In fact, by doing it (locking the page) we can easily avoid
> the nasty race balloon_isolate_page / leak_balloon, in a much simpler way, IMHO.
Absolutely. Further, we should look hard at whether most RCU uses
in this patchset can be replaced with page lock.
--
MST
next prev parent reply other threads:[~2012-08-21 19:30 UTC|newest]
Thread overview: 155+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-21 12:47 [PATCH v8 0/5] make balloon pages movable by compaction Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 12:47 ` [PATCH v8 1/5] mm: introduce a common interface for balloon pages mobility Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 13:52 ` Michael S. Tsirkin
2012-08-21 13:52 ` Michael S. Tsirkin
2012-08-21 13:52 ` Michael S. Tsirkin
2012-08-21 14:25 ` Michael S. Tsirkin
2012-08-21 14:25 ` Michael S. Tsirkin
2012-08-21 14:25 ` Michael S. Tsirkin
2012-08-21 15:16 ` Peter Zijlstra
2012-08-21 15:16 ` Peter Zijlstra
2012-08-21 15:41 ` Michael S. Tsirkin
2012-08-21 15:41 ` Michael S. Tsirkin
2012-08-21 15:41 ` Michael S. Tsirkin
2012-08-21 17:42 ` Rafael Aquini
2012-08-21 17:42 ` Rafael Aquini
2012-08-21 19:28 ` Michael S. Tsirkin
2012-08-21 19:28 ` Michael S. Tsirkin
2012-08-21 19:28 ` Michael S. Tsirkin
2012-08-21 17:42 ` Rafael Aquini
2012-08-21 15:16 ` Peter Zijlstra
2012-08-21 17:55 ` Rafael Aquini
2012-08-21 17:55 ` Rafael Aquini
2012-08-21 17:55 ` Rafael Aquini
2012-08-21 19:16 ` Michael S. Tsirkin
2012-08-21 19:16 ` Michael S. Tsirkin
2012-08-21 19:16 ` Michael S. Tsirkin
2012-08-21 19:34 ` Rafael Aquini
2012-08-21 19:34 ` Rafael Aquini
2012-08-21 19:34 ` Rafael Aquini
2012-08-22 0:06 ` Michael S. Tsirkin
2012-08-22 0:06 ` Michael S. Tsirkin
2012-08-22 0:06 ` Michael S. Tsirkin
2012-08-21 15:20 ` Peter Zijlstra
2012-08-21 15:20 ` Peter Zijlstra
2012-08-21 16:24 ` Paul E. McKenney
2012-08-21 16:24 ` Paul E. McKenney
2012-08-21 16:24 ` Paul E. McKenney
2012-08-21 17:28 ` Rafael Aquini
2012-08-21 17:28 ` Rafael Aquini
2012-08-21 17:28 ` Rafael Aquini
2012-08-21 19:13 ` Michael S. Tsirkin
2012-08-21 19:13 ` Michael S. Tsirkin
2012-08-21 19:13 ` Michael S. Tsirkin
2012-08-21 19:23 ` Rafael Aquini
2012-08-21 19:23 ` Rafael Aquini
2012-08-21 19:30 ` Michael S. Tsirkin [this message]
2012-08-21 19:30 ` Michael S. Tsirkin
2012-08-21 19:30 ` Michael S. Tsirkin
2012-08-21 20:45 ` Rafael Aquini
2012-08-21 20:45 ` Rafael Aquini
2012-08-21 20:45 ` Rafael Aquini
2012-08-22 0:07 ` Michael S. Tsirkin
2012-08-22 0:07 ` Michael S. Tsirkin
2012-08-22 0:07 ` Michael S. Tsirkin
2012-08-22 1:19 ` Rafael Aquini
2012-08-22 1:19 ` Rafael Aquini
2012-08-22 9:33 ` Michael S. Tsirkin
2012-08-22 9:33 ` Michael S. Tsirkin
2012-08-23 2:19 ` Rafael Aquini
2012-08-23 2:19 ` Rafael Aquini
2012-08-23 10:01 ` Michael S. Tsirkin
2012-08-23 10:01 ` Michael S. Tsirkin
2012-08-23 12:13 ` Rafael Aquini
2012-08-23 12:13 ` Rafael Aquini
2012-08-23 12:34 ` Michael S. Tsirkin
2012-08-23 12:34 ` Michael S. Tsirkin
2012-08-23 12:34 ` Michael S. Tsirkin
2012-08-23 13:06 ` Rafael Aquini
2012-08-23 13:06 ` Rafael Aquini
2012-08-23 13:06 ` Rafael Aquini
2012-08-23 13:53 ` Michael S. Tsirkin
2012-08-23 13:53 ` Michael S. Tsirkin
2012-08-23 13:53 ` Michael S. Tsirkin
2012-08-23 15:21 ` Rafael Aquini
2012-08-23 15:21 ` Rafael Aquini
2012-08-23 15:21 ` Rafael Aquini
2012-08-23 15:54 ` Michael S. Tsirkin
2012-08-23 15:54 ` Michael S. Tsirkin
2012-08-23 15:54 ` Michael S. Tsirkin
2012-08-23 16:03 ` Rik van Riel
2012-08-23 16:03 ` Rik van Riel
2012-08-23 16:06 ` Rafael Aquini
2012-08-23 16:06 ` Rafael Aquini
2012-08-23 16:06 ` Rafael Aquini
2012-08-23 16:10 ` Michael S. Tsirkin
2012-08-23 16:10 ` Michael S. Tsirkin
2012-08-23 16:10 ` Michael S. Tsirkin
2012-08-23 16:03 ` Rik van Riel
2012-08-23 16:25 ` Michael S. Tsirkin
2012-08-23 16:25 ` Michael S. Tsirkin
2012-08-23 17:28 ` Rafael Aquini
2012-08-23 17:28 ` Rafael Aquini
2012-08-23 17:59 ` Rik van Riel
2012-08-23 17:59 ` Rik van Riel
2012-08-23 17:59 ` Rik van Riel
2012-08-23 23:36 ` Michael S. Tsirkin
2012-08-23 23:36 ` Michael S. Tsirkin
2012-08-23 23:36 ` Michael S. Tsirkin
2012-08-24 0:26 ` Rafael Aquini
2012-08-24 0:26 ` Rafael Aquini
2012-08-24 0:26 ` Rafael Aquini
2012-08-24 0:33 ` Rafael Aquini
2012-08-24 0:33 ` Rafael Aquini
2012-08-24 0:38 ` Rafael Aquini
2012-08-24 0:38 ` Rafael Aquini
2012-08-24 0:38 ` Rafael Aquini
2012-08-24 0:49 ` Rafael Aquini
2012-08-24 0:49 ` Rafael Aquini
2012-08-24 0:49 ` Rafael Aquini
2012-08-24 0:33 ` Rafael Aquini
2012-08-24 3:12 ` Rik van Riel
2012-08-24 3:12 ` Rik van Riel
2012-08-24 8:03 ` Michael S. Tsirkin
2012-08-24 8:03 ` Michael S. Tsirkin
2012-08-24 8:03 ` Michael S. Tsirkin
2012-08-24 3:12 ` Rik van Riel
2012-08-23 17:28 ` Rafael Aquini
2012-08-23 16:25 ` Michael S. Tsirkin
2012-08-23 12:13 ` Rafael Aquini
2012-08-23 10:01 ` Michael S. Tsirkin
2012-08-23 2:19 ` Rafael Aquini
2012-08-22 9:33 ` Michael S. Tsirkin
2012-08-22 1:19 ` Rafael Aquini
2012-08-21 19:23 ` Rafael Aquini
2012-08-21 15:20 ` Peter Zijlstra
2012-08-21 12:47 ` [PATCH v8 2/5] mm: introduce compaction and migration for ballooned pages Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 12:47 ` [PATCH v8 3/5] virtio_balloon: introduce migration primitives to balloon pages Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 14:40 ` Michael S. Tsirkin
2012-08-21 14:40 ` Michael S. Tsirkin
2012-08-21 15:34 ` Peter Zijlstra
2012-08-21 15:34 ` Peter Zijlstra
2012-08-21 15:34 ` Peter Zijlstra
2012-08-21 15:37 ` Peter Zijlstra
2012-08-21 15:37 ` Peter Zijlstra
2012-08-21 15:37 ` Peter Zijlstra
2012-08-21 14:40 ` Michael S. Tsirkin
2012-08-21 14:57 ` Michael S. Tsirkin
2012-08-21 14:57 ` Michael S. Tsirkin
2012-08-21 14:57 ` Michael S. Tsirkin
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 12:47 ` [PATCH v8 4/5] mm: introduce putback_movable_pages() Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 14:42 ` Michael S. Tsirkin
2012-08-21 14:42 ` Michael S. Tsirkin
2012-08-21 14:42 ` Michael S. Tsirkin
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 12:47 ` [PATCH v8 5/5] mm: add vm event counters for balloon pages compaction Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
2012-08-21 12:47 ` Rafael Aquini
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