From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olaf Hering <olaf@aepfle.de>
Subject: Re: xentrace: broken by c/s 23050:4ebba54b666f
Date: Tue, 22 Mar 2011 15:25:33 +0100
Message-ID: <20110322142533.GA17095@aepfle.de>
References: <4D87841B.1000102@amd.com> <20110321173859.GA21766@aepfle.de>
	<20110321212320.GA15820@aepfle.de>
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To: Christoph Egger <Christoph.Egger@amd.com>
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On Mon, Mar 21, Olaf Hering wrote:

> On Mon, Mar 21, Olaf Hering wrote:
> 
> > On Mon, Mar 21, Christoph Egger wrote:
> > 
> > > 
> > > Hi,
> > > 
> > > C/s 23050:4ebba54b666f broke xentrace:
> > > 
> > > # xentrace -e 0x8f000 ./xentrace.out
> > > (XEN) Xen trace buffers: cpu 0 p 0000000000000000
> > 
> > The system you test on has 8 cpus, like mine.
> > t_info_pages got too big, so alloc_xenheap_pages() failed.
> > Can you add a printk to se whats happening in calculate_tbuf_size()?
> 
> compile tested patch:

> +    gdprintk(XENLOG_INFO, "requested %u t_info_pages for %u trace pages on %u cpus\n",
> +               t_info_pages, pages, num_online_cpus());

I can reproduce it now. For some reason the line above will print
nothing. A plain printk gives:

(XEN) requested 0 t_info_pages for 32 trace pages on 8 cpus

I will investigate.

Olaf