Re: open/stat64 syscalls run faster on Xen VM than standard Linux

[xuehai zhang <hai@cs.uchicago.edu>]

Petersson, Mats wrote:
>>-----Original Message-----
>>From: xen-devel-bounces@lists.xensource.com 
>>[mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of 
>>Anthony Liguori
>>Sent: 28 November 2005 14:39
>>To: xuehai zhang
>>Cc: Xen Mailing List
>>Subject: Re: [Xen-devel] open/stat64 syscalls run faster on 
>>Xen VM than standard Linux
>>
>>This may just be the difference between having the extra 
>>level of block caching from using a loop back device.
>>
>>Try running the same benchmark on a domain that uses an 
>>actual partition.  While the syscalls may appear to be 
>>faster, I imagine it's because the cost of pulling in a block 
>>has already been payed so the overall workload is unaffected.
> 
> 
> And this would be the same as running standard linux with the loopback
> file-system mounted and chroot to the local file-system, or would that
> be different? [I'm asking because I don't actually understand enough
> about how it works to know what difference it makes, and I would like to
> know, because at some point I'll probably need to know this.]

Mats,
I will do this experiments and see what is happening (as I promised in the popen threads).
Thanks.
Xuehai