From: Keir Fraser <keir.fraser@eu.citrix.com>
Subject: Re: [Patch] continue_hypercall_on_cpu rework using
	tasklets
Date: Wed, 14 Apr 2010 08:15:59 +0100
Message-ID: <C7EB2A3F.11376%keir.fraser@eu.citrix.com>
References: <4BC56792.2000605@ts.fujitsu.com>
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On 14/04/2010 07:58, "Juergen Gross" <juergen.gross@ts.fujitsu.com> wrote:

>> The per-cpu area method should work fine, since Xen is non-preemptive? I
>> don't think the concurrency you are concerned about can happen.
> 
> The tasklet knows only on which cpu it is running, so the data has to be
> stored on the target cpu. And one pcpu can be the target of concurrent calls
> from different calling cpus...

A tasklet also takes an arbitrary ulong parameter, which you can cast to a
pointer to your informational structure. The parameter is specified via
tasklet_init(). That should suffice.

 -- Keir