On Wednesday 10 September 2008 21:03, KAMEZAWA Hiroyuki wrote:

quoted text
> On Thu, 11 Sep 2008 06:44:37 +1000

>

> Nick Piggin  wrote:

> > On Wednesday 10 September 2008 11:49, KAMEZAWA Hiroyuki wrote:

> > > On Tue, 9 Sep 2008 18:20:48 -0700

> > >

> > > Balbir Singh  wrote:

> > > > * KAMEZAWA Hiroyuki  [2008-09-09

> > > > 21:30:12]: OK, here is approach #2, it works for me and gives me

> > > > really good performance (surpassing even the current memory

> > > > controller). I am seeing almost a 7% increase

> > >

> > > This number is from pre-allcation, maybe.

> > > We really do alloc-at-boot all page_cgroup ? This seems a big change.

> >

> > It seems really nice to me -- we get the best of both worlds, less

> > overhead for those who don't enable the memory controller, and even

> > better performance for those who do.

>

> No trobles for me for allocating-all-at-boot policy.

> My small concern is

>   - wasting page_cgroup for hugepage area.

>   - memory hotplug

In those cases you still waste the struct page area too. I realise that

isn't a good way to justify even more wastage. But I guess it is

relatively low. At least, I would think the users would be more happy to

get a 7% performance increase for small pages! :)
> > Are you expecting many users to want to turn this on and off at runtime?

quoted text
> > I wouldn't expect so, but I don't know enough about them.

>

> There is no runtime switch. only at boot.

Fine
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