Modify region_add() to keep track of regions(pages) added to the
reserve map and return this value.  The return value can be
compared to the return value of region_chg() to determine if the
map was modified between calls.  Make vma_commit_reservation()
also pass along the return value of region_add().  The special
case return values of vma_needs_reservation() should also be
taken into account when determining the return value of
vma_commit_reservation().

Signed-off-by: Mike Kravetz <mike.krav...@oracle.com>
---
 mm/hugetlb.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c41b2a0..7f64034 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -156,6 +156,7 @@ static long region_add(struct resv_map *resv, long f, long 
t)
 {
        struct list_head *head = &resv->regions;
        struct file_region *rg, *nrg, *trg;
+       long chg = 0;
 
        spin_lock(&resv->lock);
        /* Locate the region we are either in or before. */
@@ -181,14 +182,17 @@ static long region_add(struct resv_map *resv, long f, 
long t)
                if (rg->to > t)
                        t = rg->to;
                if (rg != nrg) {
+                       chg -= (rg->to - rg->from);
                        list_del(&rg->link);
                        kfree(rg);
                }
        }
+       chg += (nrg->from - f);
        nrg->from = f;
+       chg += t - nrg->to;
        nrg->to = t;
        spin_unlock(&resv->lock);
-       return 0;
+       return chg;
 }
 
 static long region_chg(struct resv_map *resv, long f, long t)
@@ -1349,18 +1353,25 @@ static long vma_needs_reservation(struct hstate *h,
        else
                return chg < 0 ? chg : 0;
 }
-static void vma_commit_reservation(struct hstate *h,
+
+static long vma_commit_reservation(struct hstate *h,
                        struct vm_area_struct *vma, unsigned long addr)
 {
        struct resv_map *resv;
        pgoff_t idx;
+       long add;
 
        resv = vma_resv_map(vma);
        if (!resv)
-               return;
+               return 1;
 
        idx = vma_hugecache_offset(h, vma, addr);
-       region_add(resv, idx, idx + 1);
+       add = region_add(resv, idx, idx + 1);
+
+       if (vma->vm_flags & VM_MAYSHARE)
+               return add;
+       else
+               return 0;
 }
 
 static struct page *alloc_huge_page(struct vm_area_struct *vma,
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to