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Date: Mon, 23 Apr 2018 15:09:11 +0100
From: Wei Liu <wei.liu2@citrix.com>
To: Dongli Zhang <dongli.zhang@oracle.com>
CC: <xen-devel@lists.xenproject.org>, <linux-kernel@vger.kernel.org>,
        <boris.ostrovsky@oracle.com>, <jgross@suse.com>,
        <ian.jackson@eu.citrix.com>, <wei.liu2@citrix.com>,
        <srinivas.eeda@oracle.com>
Subject: Re: [RFC 0/2] To introduce xenwatch multithreading (xen mtwatch)
Message-ID: <20180423140911.bihiwfwtlneobgzd@citrix.com>
References: <1523100355-27647-1-git-send-email-dongli.zhang@oracle.com>
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On Sat, Apr 07, 2018 at 07:25:53PM +0800, Dongli Zhang wrote:
> About per-domU xenwatch thread create/destroy, a new type of xenstore node is
> introduced: '/local/domain/0/mtwatch/<domid>'.
> 
> Suppose the new domid id 7. During the domU (domid=7) creation, the xen
> toolstack writes '/local/domain/0/mtwatch/7' to xenstore before the insertion
> of '/local/domain/7'. When the domid=7 is destroyed, the last xenstore
> operation by xen toolstack is to remove '/local/domain/0/mtwatch/7'.
> 
> The dom0 kernel subscribes a watch at node '/local/domain/0/mtwatch'.  Kernel
> thread [xen-mtwatch-7] is created when '/local/domain/0/mtwatch/7' is inserted,
> while this kernel thread is destroyed when the corresponding xenstore node is
> removed.

Instead of inventing yet another node, can you not watch /local/domain
directly?

Wei.