From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <20080410171101.551336000@nick.local0.net> References: <20080410170232.015351000@nick.local0.net> Date: Fri, 11 Apr 2008 03:02:43 +1000 From: npiggin@suse.de Subject: [patch 11/17] hugetlbfs: support larger than MAX_ORDER Content-Disposition: inline; filename=hugetlb-unlimited-order.patch Sender: owner-linux-mm@kvack.org Return-Path: To: akpm@linux-foundation.org Cc: Andi Kleen , linux-kernel@vger.kernel.org, linux-mm@kvack.org, pj@sgi.com, andi@firstfloor.org, kniht@linux.vnet.ibm.com List-ID: This is needed on x86-64 to handle GB pages in hugetlbfs, because it is not practical to enlarge MAX_ORDER to 1GB. Instead the 1GB pages are only allocated at boot using the bootmem allocator using the hugepages=... option. These 1G bootmem pages are never freed. In theory it would be possible to implement that with some complications, but since it would be a one-way street (> MAX_ORDER pages cannot be allocated later) I decided not to currently. The > MAX_ORDER code is not ifdef'ed per architecture. It is not very big and the ifdef uglyness seemed not be worth it. Known problems: /proc/meminfo and "free" do not display the memory allocated for gb pages in "Total". This is a little confusing for the user. Signed-off-by: Andi Kleen Signed-off-by: Nick Piggin To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: pj@sgi.com Cc: andi@firstfloor.org Cc: kniht@linux.vnet.ibm.com --- mm/hugetlb.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 62 insertions(+), 2 deletions(-) Index: linux-2.6/mm/hugetlb.c =================================================================== --- linux-2.6.orig/mm/hugetlb.c +++ linux-2.6/mm/hugetlb.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -158,7 +159,7 @@ static void free_huge_page(struct page * INIT_LIST_HEAD(&page->lru); spin_lock(&hugetlb_lock); - if (h->surplus_huge_pages_node[nid]) { + if (h->surplus_huge_pages_node[nid] && h->order <= MAX_ORDER) { update_and_free_page(h, page); h->surplus_huge_pages--; h->surplus_huge_pages_node[nid]--; @@ -220,6 +221,9 @@ static struct page *alloc_fresh_huge_pag { struct page *page; + if (h->order > MAX_ORDER) + return NULL; + page = alloc_pages_node(nid, htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|__GFP_NOWARN, huge_page_order(h)); @@ -276,6 +280,9 @@ static struct page *alloc_buddy_huge_pag struct page *page; unsigned int nid; + if (h->order > MAX_ORDER) + return NULL; + /* * Assume we will successfully allocate the surplus page to * prevent racing processes from causing the surplus to exceed @@ -442,6 +449,10 @@ static void return_unused_surplus_pages( /* Uncommit the reservation */ h->resv_huge_pages -= unused_resv_pages; + /* Cannot return gigantic pages currently */ + if (h->order > MAX_ORDER) + return; + nr_pages = min(unused_resv_pages, h->surplus_huge_pages); while (remaining_iterations-- && nr_pages) { @@ -520,6 +531,44 @@ static struct page *alloc_huge_page(stru return page; } +static __initdata LIST_HEAD(huge_boot_pages); + +struct huge_bm_page { + struct list_head list; + struct hstate *hstate; +}; + +static int __init alloc_bm_huge_page(struct hstate *h) +{ + struct huge_bm_page *m; + m = __alloc_bootmem_node_nopanic(NODE_DATA(h->hugetlb_next_nid), + huge_page_size(h), huge_page_size(h), + 0); + if (!m) + return 0; + BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1)); + /* Put them into a private list first because mem_map is not up yet */ + list_add(&m->list, &huge_boot_pages); + m->hstate = h; + hstate_next_node(h); + return 1; +} + +/* Put bootmem huge pages into the standard lists after mem_map is up */ +static int __init huge_init_bm(void) +{ + struct huge_bm_page *m; + list_for_each_entry (m, &huge_boot_pages, list) { + struct page *page = virt_to_page(m); + struct hstate *h = m->hstate; + __ClearPageReserved(page); + prep_compound_page(page, h->order); + huge_new_page(h, page); + } + return 0; +} +__initcall(huge_init_bm); + static int __init hugetlb_init_hstate(struct hstate *h) { unsigned long i; @@ -535,7 +584,10 @@ static int __init hugetlb_init_hstate(st h->hugetlb_next_nid = first_node(node_online_map); for (i = 0; i < max_huge_pages[h - hstates]; ++i) { - if (!alloc_fresh_huge_page(h)) + if (h->order > MAX_ORDER) { + if (!alloc_bm_huge_page(h)) + break; + } else if (!alloc_fresh_huge_page(h)) break; } max_huge_pages[h - hstates] = h->free_huge_pages = h->nr_huge_pages = i; @@ -594,6 +646,9 @@ static void try_to_free_low(struct hstat { int i; + if (h->order > MAX_ORDER) + return; + for (i = 0; i < MAX_NUMNODES; ++i) { struct page *page, *next; struct list_head *freel = &h->hugepage_freelists[i]; @@ -623,6 +678,11 @@ set_max_huge_pages(struct hstate *h, uns *err = 0; + if (h->order > MAX_ORDER) { + *err = -EINVAL; + return max_huge_pages[h - hstates]; + } + /* * Increase the pool size * First take pages out of surplus state. Then make up the -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org