From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olaf Hering <olaf@aepfle.de>
Subject: Re: Re: how to handle paged hypercall args?
Date: Fri, 3 Dec 2010 10:03:41 +0100
Message-ID: <20101203090341.GA6055@aepfle.de>
References: <20101115120459.GF21112@whitby.uk.xensource.com>
	<C906D549.9F92%keir@xen.org>
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To: Keir Fraser <keir@xen.org>
Cc: Patrick Colp <pjcolp@cs.ubc.ca>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Tim Deegan <Tim.Deegan@citrix.com>, Jan Beulich <JBeulich@novell.com>
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On Mon, Nov 15, Keir Fraser wrote:

> On 15/11/2010 12:04, "Tim Deegan" <Tim.Deegan@citrix.com> wrote:

> > Will it
> > need per-vcpu stacks? (and will they, in turn, use order>0 allocations? :))
> 
> Of a sort. I propose to keep the per-pcpu stacks and then copy context
> to/from a per-vcpu memory area for the setjmp-like behaviour. Guest call
> stacks won't be very deep -- I reckon a 1kB or 2kB per-vcpu area will
> suffice.

Keir,

in my testing the BUG_ON in __prepare_to_wait() triggers, 1500 is too
small. I changed it to 4096 - (4*sizeof(void*)) to fix it for me.
3K would be enough as well.
How large can the stack get, is there an upper limit?

Olaf