hugetlb: support boot allocate different sizes

Make some infrastructure changes to allow boot-time allocation of
different hugepage page sizes.

- move all basic hstate initialisation into hugetlb_add_hstate
- create a new function hugetlb_hstate_alloc_pages() to do the
  actual initial page allocations. Call this function early in
  order to allocate giant pages from bootmem.
- Check for multiple hugepages= parameters

Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Andrew Hastings <abh@cray.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 1a6fe87555b286d23c5d6ce770873f062ff1c3e3..243a8684d180c127729c1aaa3ce3702bac52edd2 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -981,15 +981,10 @@ static void __init gather_bootmem_prealloc(void)
        }
 }
 
-static void __init hugetlb_init_one_hstate(struct hstate *h)
+static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
 {
        unsigned long i;
 
-       for (i = 0; i < MAX_NUMNODES; ++i)
-               INIT_LIST_HEAD(&h->hugepage_freelists[i]);
-
-       h->hugetlb_next_nid = first_node(node_online_map);
-
        for (i = 0; i < h->max_huge_pages; ++i) {
                if (h->order >= MAX_ORDER) {
                        if (!alloc_bootmem_huge_page(h))
@@ -997,7 +992,7 @@ static void __init hugetlb_init_one_hstate(struct hstate *h)
                } else if (!alloc_fresh_huge_page(h))
                        break;
        }
-       h->max_huge_pages = h->free_huge_pages = h->nr_huge_pages = i;
+       h->max_huge_pages = i;
 }
 
 static void __init hugetlb_init_hstates(void)
@@ -1005,7 +1000,9 @@ static void __init hugetlb_init_hstates(void)
        struct hstate *h;
 
        for_each_hstate(h) {
-               hugetlb_init_one_hstate(h);
+               /* oversize hugepages were init'ed in early boot */
+               if (h->order < MAX_ORDER)
+                       hugetlb_hstate_alloc_pages(h);
        }
 }
 
@@ -1301,6 +1298,8 @@ module_init(hugetlb_init);
 void __init hugetlb_add_hstate(unsigned order)
 {
        struct hstate *h;
+       unsigned long i;
+
        if (size_to_hstate(PAGE_SIZE << order)) {
                printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
                return;
@@ -1310,15 +1309,21 @@ void __init hugetlb_add_hstate(unsigned order)
        h = &hstates[max_hstate++];
        h->order = order;
        h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
+       h->nr_huge_pages = 0;
+       h->free_huge_pages = 0;
+       for (i = 0; i < MAX_NUMNODES; ++i)
+               INIT_LIST_HEAD(&h->hugepage_freelists[i]);
+       h->hugetlb_next_nid = first_node(node_online_map);
        snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
                                        huge_page_size(h)/1024);
-       hugetlb_init_one_hstate(h);
+
        parsed_hstate = h;
 }
 
 static int __init hugetlb_setup(char *s)
 {
        unsigned long *mhp;
+       static unsigned long *last_mhp;
 
        /*
         * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
@@ -1329,9 +1334,25 @@ static int __init hugetlb_setup(char *s)
        else
                mhp = &parsed_hstate->max_huge_pages;
 
+       if (mhp == last_mhp) {
+               printk(KERN_WARNING "hugepages= specified twice without "
+                       "interleaving hugepagesz=, ignoring\n");
+               return 1;
+       }
+
        if (sscanf(s, "%lu", mhp) <= 0)
                *mhp = 0;
 
+       /*
+        * Global state is always initialized later in hugetlb_init.
+        * But we need to allocate >= MAX_ORDER hstates here early to still
+        * use the bootmem allocator.
+        */
+       if (max_hstate && parsed_hstate->order >= MAX_ORDER)
+               hugetlb_hstate_alloc_pages(parsed_hstate);
+
+       last_mhp = mhp;
+
        return 1;
 }
 __setup("hugepages=", hugetlb_setup);