Re: Hugepages demand paging V1 [4/4]: Numa patch

[William Lee Irwin III <wli@holomorphy.com>]

On Thu, Oct 21, 2004 at 09:58:54PM -0700, Christoph Lameter wrote:
> Changelog
> 	* NUMA enhancements (rough first implementation)
> 	* Do not begin search for huge page memory at the first node
> 	  but start at the current node and then search previous and
> 	  the following nodes for memory.
> Signed-off-by: Christoph Lameter <clameter@sgi.com>

dequeue_huge_page() seems to want a nodemask, not a vma, though I
suppose it's not particularly pressing.


> Index: linux-2.6.9/mm/hugetlb.c
> ===================================================================
> --- linux-2.6.9.orig/mm/hugetlb.c	2004-10-21 20:39:50.000000000 -0700
> +++ linux-2.6.9/mm/hugetlb.c	2004-10-21 20:44:12.000000000 -0700
> @@ -28,15 +28,30 @@
>  	free_huge_pages_node[nid]++;
>  }
> 
> -static struct page *dequeue_huge_page(void)
> +static struct page *dequeue_huge_page(struct vm_area_struct *vma, unsigned long addr)
>  {
>  	int nid = numa_node_id();
> +	int tid, nid2;
>  	struct page *page = NULL;
> 
>  	if (list_empty(&hugepage_freelists[nid])) {
> -		for (nid = 0; nid < MAX_NUMNODES; ++nid)
> -			if (!list_empty(&hugepage_freelists[nid]))
> -				break;
> +		/* Prefer the neighboring nodes */
> +		for (tid =1 ; tid < MAX_NUMNODES; tid++) {
> +
> +			/* Is there space in a following node ? */
> +			nid2 = (nid + tid) % MAX_NUMNODES;
> +			if (mpol_node_valid(nid2, vma, addr) &&
> +				!list_empty(&hugepage_freelists[nid2]))
> +					break;
> +
> +			/* or in an previous node ? */
> +			if (tid > nid) continue;
> +			nid2 = nid - tid;
> +			if (mpol_node_valid(nid2, vma, addr) &&
> +				!list_empty(&hugepage_freelists[nid2]))
> +					break;
> +		}
> +		nid = nid2;
>  	}
>  	if (nid >= 0 && nid < MAX_NUMNODES &&
>  	    !list_empty(&hugepage_freelists[nid])) {
> @@ -75,13 +90,13 @@
>  	spin_unlock(&hugetlb_lock);
>  }
> 
> -struct page *alloc_huge_page(void)
> +struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr)
>  {
>  	struct page *page;
>  	int i;
> 
>  	spin_lock(&hugetlb_lock);
> -	page = dequeue_huge_page();
> +	page = dequeue_huge_page(vma, addr);
>  	if (!page) {
>  		spin_unlock(&hugetlb_lock);
>  		return NULL;
> @@ -181,7 +196,7 @@
>  	spin_lock(&hugetlb_lock);
>  	try_to_free_low(count);
>  	while (count < nr_huge_pages) {
> -		struct page *page = dequeue_huge_page();
> +		struct page *page = dequeue_huge_page(NULL, 0);
>  		if (!page)
>  			break;
>  		update_and_free_page(page);
> @@ -255,7 +270,7 @@
>  retry:
>  	page = find_get_page(mapping, idx);
>  	if (!page) {
> -		page = alloc_huge_page();
> +		page = alloc_huge_page(vma, addr);
>  		if (!page)
>  			/*
>  			 * with strict overcommit accounting, we should never
> Index: linux-2.6.9/include/linux/hugetlb.h
> ===================================================================
> --- linux-2.6.9.orig/include/linux/hugetlb.h	2004-10-21 20:44:10.000000000 -0700
> +++ linux-2.6.9/include/linux/hugetlb.h	2004-10-21 20:44:56.000000000 -0700
> @@ -31,7 +31,7 @@
>  				pmd_t *pmd, int write);
>  int is_aligned_hugepage_range(unsigned long addr, unsigned long len);
>  int pmd_huge(pmd_t pmd);
> -struct page *alloc_huge_page(void);
> +struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr);
>  void free_huge_page(struct page *);
> 
>  extern unsigned long max_huge_pages;
>