Re: [patch 1/3] mm: An enhancement of OVERCOMMIT_GUESS

[Hideo AOKI <haoki@redhat.com>]

Hi Kamezawa-san,

Thank you for your comments.

KAMEZAWA Hiroyuki wrote:
> Hi, AOKI-san
> 
> On Wed, 05 Apr 2006 19:47:27 -0400
> Hideo AOKI <haoki@redhat.com> wrote:
> 
> 
>>Hello Andrew,
>>
>>Could you apply my patches to your tree?
>>
>>These patches are an enhancement of OVERCOMMIT_GUESS algorithm in
>>__vm_enough_memory(). The detailed description is in attached patch.
> 
> I think adding a function like this is more simple way.
> (call this istead of nr_free_pages().)
> ==
> int nr_available_memory() 
> {
> 	unsigned long sum = 0;
> 	for_each_zone(zone) {
> 		if (zone->free_pages > zone->pages_high)
> 			sum += zone->free_pages - zone->pages_high;
> 	}
> 	return sum;
> }
> ==

I like your idea. But, in the function, I think we need to care
lowmem_reserve too.

Since __vm_enough_memory() doesn't know zone and cpuset information,
we have to guess proper value of lowmem_reserve in each zone
like I did in calculate_totalreserve_pages() in my patch.
Do you think that we can do this calculation every time?

If it is good enough, I'll make revised patch.


> BTW, vm_enough_memory() doesn't eat cpuset information ?

I think this is another point which we should improve.

Best regards,
Hideo Aoki

---
Hideo Aoki, Hitachi Computer Products (America) Inc.