lkml.org 
[lkml]   [2009]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 26/35] Use the per-cpu allocator for orders up to PAGE_ALLOC_COSTLY_ORDER
On Mon, Mar 16, 2009 at 12:26:07PM -0400, Christoph Lameter wrote:
> On Mon, 16 Mar 2009, Mel Gorman wrote:
>
> > -static void free_hot_cold_page(struct page *page, int cold)
> > +static void free_hot_cold_page(struct page *page, int order, int cold)
> > {
> > struct zone *zone = page_zone(page);
> > struct per_cpu_pages *pcp;
> > unsigned long flags;
> > int clearMlocked = PageMlocked(page);
> >
> > + /* SLUB can return lowish-order compound pages that need handling */
> > + if (order > 0 && unlikely(PageCompound(page)))
> > + if (unlikely(destroy_compound_page(page, order)))
> > + return;
> > +
>
> Isnt that also true for stacks and generic network objects ==- 8k?
>

I think they are vanilla high-order pages, not compound pages.

> > again:
> > cpu = get_cpu();
> > - if (likely(order == 0)) {
> > + if (likely(order <= PAGE_ALLOC_COSTLY_ORDER)) {
> > struct per_cpu_pages *pcp;
> > + int batch;
> > + int delta;
> >
> > pcp = &zone_pcp(zone, cpu)->pcp;
> > + batch = max(1, pcp->batch >> order);
> > local_irq_save(flags);
> > if (!pcp->count) {
> > - pcp->count = rmqueue_bulk(zone, 0,
> > - pcp->batch, &pcp->list, migratetype);
> > + delta = rmqueue_bulk(zone, order, batch,
> > + &pcp->list, migratetype);
> > + bulk_add_pcp_page(pcp, order, delta);
> > if (unlikely(!pcp->count))
> > goto failed;
>
> The pcp adds a series of order N pages if an order N alloc occurs and the
> queue is empty?
>

Nope, that would be bad. The calculation of batch is made above and is

batch = max(1, pcp->batch >> order);

so order is taken into account when deciding how many pages to allocate.

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab


\
 
 \ /
  Last update: 2009-03-16 17:49    [W:0.326 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site