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From: "Américo Wang" <xiyou.wangcong@gmail.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: "Américo Wang" <xiyou.wangcong@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: 2.6.33 pagemap endless read loop
Date: Tue, 12 Jan 2010 23:32:08 +0800	[thread overview]
Message-ID: <20100112153208.GF3925@hack> (raw)
In-Reply-To: <20100110123702.GC25323@basil.fritz.box>

On Sun, Jan 10, 2010 at 01:37:02PM +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.
>

Hmm, could you please try:

     time cat /proc/self/pagemap >/dev/null

? Is it much faster than:

     time cat /proc/self/pagemap

?

Thanks!
-- 
Live like a child, think like the god.
 

  parent reply	other threads:[~2010-01-12 15:30 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-10  2:09 2.6.33 pagemap endless read loop Andi Kleen
2010-01-10  6:33 ` Américo Wang
2010-01-10 12:37   ` Andi Kleen
2010-01-12  5:59     ` Mike Galbraith
2010-01-12 15:32     ` Américo Wang [this message]
2010-01-12 16:28       ` Andi Kleen
2010-01-13  2:08         ` Américo Wang
     [not found] ` <20100113141648.42eff724.akpm@linux-foundation.org>
     [not found]   ` <1263421562.29868.5000.camel@calx>
     [not found]     ` <20100113143055.7bea30c5.akpm@linux-foundation.org>
     [not found]       ` <1263423916.29868.5009.camel@calx>
     [not found]         ` <20100113151502.fa425247.akpm@linux-foundation.org>
     [not found]           ` <20100114055319.GA17671@localhost>
     [not found]             ` <20100113221013.b1beecb4.akpm@linux-foundation.org>
2010-01-14  8:06               ` Wu Fengguang
2010-01-14  8:30                 ` Andi Kleen
2010-01-14  8:52                   ` [PATCH] pagemap: early return on unmapped areas Wu Fengguang
2010-01-14 17:02                     ` Matt Mackall

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