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From: Anthony Liguori <aliguori@us.ibm.com>
To: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	kvm-devel <kvm@vger.kernel.org>
Subject: Live migration broken when under heavy IO
Date: Mon, 15 Jun 2009 15:33:41 -0500	[thread overview]
Message-ID: <4A36B025.2080602@us.ibm.com> (raw)

The basic issue is that:

migrate_fd_put_ready():    bdrv_flush_all();

Does:

block.c:

foreach block driver:
   drv->flush(bs);

Which in the case of raw, is just fsync(s->fd).

Any submitted request is not queued or flushed which will lead to the 
request being dropped after the live migration.

Is anyone working on fixing this?  Does anyone have a clever idea how to 
fix this without just waiting for all IO requests to complete?

---

Regards,

Anthony Liguori


             reply	other threads:[~2009-06-15 20:33 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-15 20:33 Anthony Liguori [this message]
2009-06-15 20:48 ` [Qemu-devel] Live migration broken when under heavy IO Glauber Costa
2009-06-16  9:10 ` Avi Kivity
2009-06-16  9:13   ` Avi Kivity
2009-06-16 12:50   ` Anthony Liguori
2009-06-16 12:54     ` Avi Kivity
2009-06-16 12:57       ` Anthony Liguori
2009-06-16 13:12         ` Avi Kivity

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