Subject: Re: 2.6.33 pagemap endless read loop
From: Mike Galbraith <efault@gmx.de>
To: Andi Kleen <andi@firstfloor.org>
Cc: =?ISO-8859-1?Q?Am=E9rico?= Wang <xiyou.wangcong@gmail.com>,
       linux-kernel@vger.kernel.org
In-Reply-To: <20100110123702.GC25323@basil.fritz.box>
References: <20100110020955.GB25323@basil.fritz.box>
	 <20100110063335.GA3005@hack>  <20100110123702.GC25323@basil.fritz.box>
Content-Type: text/plain
Date: Tue, 12 Jan 2010 06:59:59 +0100
Message-Id: <1263275999.5987.26.camel@marge.simson.net>
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1096
Lines: 35

On Sun, 2010-01-10 at 13:37 +0100, Andi Kleen wrote:
> > Are you sure
> 
> I don't know if it's really endless, but it's doing a good emulation
> of it if it's not.
> 
> > 
> > On my 32bit machine, it runs for a long time, but finally exits.
> 
> That was on 64bit.
> 
> proc01 had accumulated several minutes of CPU time when I stopped it.
> 
> > From the document of pagemap, it is the mapping of all the virtual pages
> > of a process, on x86-32, it should be 4G/4K = 1024*1024 pages, also
> 
> Only the mapped ones surely?
> 
> Right now it looks like it dumps all the holes and that obviously
> will never finish on 64bit which has 47bits of address space.

Takes forever if you whack .pagemap_pte_hole too, just spends it's life
in pagemap_pte_range() instead.

start_vaddr:0x0 end_vaddr:0x7ffffffff000

Hm, zillion paces ain't a walk.

	-Mike

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/