hugetlb: multiple hstates for multiple page sizes

Add basic support for more than one hstate in hugetlbfs.  This is the key
to supporting multiple hugetlbfs page sizes at once.

- Rather than a single hstate, we now have an array, with an iterator
- default_hstate continues to be the struct hstate which we use by default
- Add functions for architectures to register new hstates

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.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>

1 files changed, 5 insertions, 3 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 1f7b3b76a166..1a8299d1fe59 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -959,7 +959,7 @@ static struct ctl_table vm_table[] = {
 #ifdef CONFIG_HUGETLB_PAGE
          {
                 .procname       = "nr_hugepages",
-                .data           = &max_huge_pages,
+                .data           = NULL,
                 .maxlen         = sizeof(unsigned long),
                 .mode           = 0644,
                 .proc_handler   = &hugetlb_sysctl_handler,
@@ -985,10 +985,12 @@ static struct ctl_table vm_table[] = {
         {
                 .ctl_name       = CTL_UNNUMBERED,
                 .procname       = "nr_overcommit_hugepages",
-                .data           = &sysctl_overcommit_huge_pages,
-                .maxlen         = sizeof(sysctl_overcommit_huge_pages),
+                .data           = NULL,
+                .maxlen         = sizeof(unsigned long),
                 .mode           = 0644,
                 .proc_handler   = &hugetlb_overcommit_handler,
+                .extra1         = (void *)&hugetlb_zero,
+                .extra2         = (void *)&hugetlb_infinity,
         },
 #endif
         {