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Date: Mon, 15 Apr 2013 08:38:55 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 2/5] hostmem: make hostmem global and RAM
	hotunplg safe
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To: liu ping fan <qemulist@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>, Anthony Liguori <aliguori@us.ibm.com>, Stefan Hajnoczi <stefanha@gmail.com>, Marcelo Tosatti <mtosatti@redhat.com>, qemu-devel@nongnu.org, Vasilis Liaskovitis <vasilis.liaskovitis@profitbricks.com>, Jan Kiszka <jan.kiszka@siemens.com>

Il 15/04/2013 03:42, liu ping fan ha scritto:
> > It will work because readers will grab either the hostmem_lock or the
> > BQL, while writers will grab both.  A kind of local/global lock, but I'm
> 
> No only hostmem_lock is used to protect readers from writers.  While
> the writers are protected agaist each other by biglock.  So leaving
> the "cur_hostmem = next_hostmem" outside to reflect the lock's rules.

Doesn't help much if you do not document them...

Paolo