From 396faf0303d273219db5d7eb4a2879ad977ed185 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 17 Jul 2007 04:03:13 -0700 Subject: Allow huge page allocations to use GFP_HIGH_MOVABLE Huge pages are not movable so are not allocated from ZONE_MOVABLE. However, as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it can be used to satisfy hugepage allocations even when the system has been running a long time. This allows an administrator to resize the hugepage pool at runtime depending on the size of ZONE_MOVABLE. This patch adds a new sysctl called hugepages_treat_as_movable. When a non-zero value is written to it, future allocations for the huge page pool will use ZONE_MOVABLE. Despite huge pages being non-movable, we do not introduce additional external fragmentation of note as huge pages are always the largest contiguous block we care about. [akpm@linux-foundation.org: various fixes] Signed-off-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index acc0fb3cf067..58980676b842 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -27,6 +27,9 @@ unsigned long max_huge_pages; static struct list_head hugepage_freelists[MAX_NUMNODES]; static unsigned int nr_huge_pages_node[MAX_NUMNODES]; static unsigned int free_huge_pages_node[MAX_NUMNODES]; +static gfp_t htlb_alloc_mask = GFP_HIGHUSER; +unsigned long hugepages_treat_as_movable; + /* * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages */ @@ -68,12 +71,13 @@ static struct page *dequeue_huge_page(struct vm_area_struct *vma, { int nid; struct page *page = NULL; - struct zonelist *zonelist = huge_zonelist(vma, address); + struct zonelist *zonelist = huge_zonelist(vma, address, + htlb_alloc_mask); struct zone **z; for (z = zonelist->zones; *z; z++) { nid = zone_to_nid(*z); - if (cpuset_zone_allowed_softwall(*z, GFP_HIGHUSER) && + if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) && !list_empty(&hugepage_freelists[nid])) break; } @@ -113,7 +117,7 @@ static int alloc_fresh_huge_page(void) prev_nid = nid; spin_unlock(&nid_lock); - page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, + page = alloc_pages_node(nid, htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN, HUGETLB_PAGE_ORDER); if (page) { set_compound_page_dtor(page, free_huge_page); @@ -263,6 +267,19 @@ int hugetlb_sysctl_handler(struct ctl_table *table, int write, max_huge_pages = set_max_huge_pages(max_huge_pages); return 0; } + +int hugetlb_treat_movable_handler(struct ctl_table *table, int write, + struct file *file, void __user *buffer, + size_t *length, loff_t *ppos) +{ + proc_dointvec(table, write, file, buffer, length, ppos); + if (hugepages_treat_as_movable) + htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; + else + htlb_alloc_mask = GFP_HIGHUSER; + return 0; +} + #endif /* CONFIG_SYSCTL */ int hugetlb_report_meminfo(char *buf) -- cgit v1.2.3-55-g7522