|
|
|
|
|
|
|
|
|
|
xen-devel
[Xen-devel] Re: [PATCH] Add hypercall to mark superpages to improve perf
On Friday 30 April 2010, Keir Fraser wrote:
> One option would be an array of reference counts indexed by superpage
> number (i.e, mfn>>9). So kind of a separate array to page_info, and a
> non-zero superpage refcount would arrange to hold a reference on every
> relevant page in page_info.
>
> That could be implemented with no extra hypercalls, and I reckon it's
> probably easier to make this race-free too. Obviously it does have extra
> code complexity to construct this array (which I suppose needs to be
> sparse, just like page_info array, in the face of very sparse memory
> maps). The space overhead (about 8 bytes per 2MB, or 0.0004% of total
> system memory) would be trivial. Compared with an extra reference count in
> every page_info, which would have a much higher 0.2% overhead.
I like this idea. I'll look into it.
Dave
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
|
|