Re: [PATCH] xenpaging:add a new array to speed up page-in in xenpaging

[Olaf Hering <olaf@aepfle.de>]

On Sat, Jan 07, Hongkaixing wrote:

> 
> > -----Original Message-----
> > From: Olaf Hering [mailto:olaf@aepfle.de]
> > Sent: Friday, January 06, 2012 9:08 PM
> > To: hongkaixing@huawei.com
> > Cc: xen-devel@lists.xensource.com
> > Subject: Re: [PATCH] xenpaging:add a new array to speed up page-in in xenpaging
> > 
> > On Thu, Jan 05, Olaf Hering wrote:
> > 
> > > Is the page-out time for 512M really that fast? For me page-out is still
> > > really slow even when the pagefile is in tmpfs. It takes several
> > > minutes, I get around 4MB/s. page-in is around 20MB/s.
> > 
> > Wait, the slow page-out is due to the poll() timeout in
> > xenpaging_wait_for_event_or_timeout(). This can be fixed with some sort
> > of dynamic timeout while there is still something to page-out.
> 
>    I don't think so. Our approach still use 100ms in poll(), Using 10ms seems no significant change.

Sure, I was talking about page-out. With my change to use no timeout for
poll() the guests memory was paged-out in a few seconds.
I will send a patch for that today.

page-in is still slow as you know, we need to improve that in some way.

Olaf