lkml.org 
[lkml]   [2013]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 06/18] mm, hugetlb: remove vma_need_reservation()
Date
vma_need_reservation() can be substituted by vma_has_reserves()
with minor change. These function do almost same thing,
so unifying them is better to maintain.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index bf2ee11..ff46a2c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -451,8 +451,18 @@ void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
vma->vm_private_data = (void *)0;
}

-/* Returns true if the VMA has associated reserve pages */
-static int vma_has_reserves(struct vm_area_struct *vma, long chg)
+/*
+ * Determine if the huge page at addr within the vma has an associated
+ * reservation. Where it does not we will need to logically increase
+ * reservation and actually increase subpool usage before an allocation
+ * can occur. Where any new reservation would be required the
+ * reservation change is prepared, but not committed. Once the page
+ * has been allocated from the subpool and instantiated the change should
+ * be committed via vma_commit_reservation. No action is required on
+ * failure.
+ */
+static int vma_has_reserves(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long addr)
{
if (vma->vm_flags & VM_NORESERVE) {
/*
@@ -464,10 +474,22 @@ static int vma_has_reserves(struct vm_area_struct *vma, long chg)
* step. Currently, we don't have any other solution to deal
* with this situation properly, so add work-around here.
*/
- if (vma->vm_flags & VM_MAYSHARE && chg == 0)
- return 1;
- else
- return 0;
+ if (vma->vm_flags & VM_MAYSHARE) {
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ struct inode *inode = mapping->host;
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ struct resv_map *resv = inode->i_mapping->private_data;
+ long chg;
+
+ chg = region_chg(resv, idx, idx + 1);
+ if (chg < 0)
+ return -ENOMEM;
+
+ if (chg == 0)
+ return 1;
+ }
+
+ return 0;
}

/* Shared mappings always use reserves */
@@ -478,8 +500,16 @@ static int vma_has_reserves(struct vm_area_struct *vma, long chg)
* Only the process that called mmap() has reserves for
* private mappings.
*/
- if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
+ if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ struct resv_map *resv = vma_resv_map(vma);
+
+ /* Just for allocating region structure */
+ if (region_chg(resv, idx, idx + 1) < 0)
+ return -ENOMEM;
+
return 1;
+ }

return 0;
}
@@ -542,8 +572,7 @@ static struct page *dequeue_huge_page_node(struct hstate *h, int nid)

static struct page *dequeue_huge_page_vma(struct hstate *h,
struct vm_area_struct *vma,
- unsigned long address, int avoid_reserve,
- long chg)
+ unsigned long address, int avoid_reserve)
{
struct page *page = NULL;
struct mempolicy *mpol;
@@ -558,7 +587,7 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
* have no page reserves. This check ensures that reservations are
* not "stolen". The child may still get SIGKILLed
*/
- if (!vma_has_reserves(vma, chg) &&
+ if (!vma_has_reserves(h, vma, address) &&
h->free_huge_pages - h->resv_huge_pages == 0)
return NULL;

@@ -578,7 +607,7 @@ retry_cpuset:
if (page) {
if (avoid_reserve)
break;
- if (!vma_has_reserves(vma, chg))
+ if (!vma_has_reserves(h, vma, address))
break;

h->resv_huge_pages--;
@@ -1077,42 +1106,6 @@ static void return_unused_surplus_pages(struct hstate *h,
}
}

-/*
- * Determine if the huge page at addr within the vma has an associated
- * reservation. Where it does not we will need to logically increase
- * reservation and actually increase subpool usage before an allocation
- * can occur. Where any new reservation would be required the
- * reservation change is prepared, but not committed. Once the page
- * has been allocated from the subpool and instantiated the change should
- * be committed via vma_commit_reservation. No action is required on
- * failure.
- */
-static long vma_needs_reservation(struct hstate *h,
- struct vm_area_struct *vma, unsigned long addr)
-{
- struct address_space *mapping = vma->vm_file->f_mapping;
- struct inode *inode = mapping->host;
-
- if (vma->vm_flags & VM_MAYSHARE) {
- pgoff_t idx = vma_hugecache_offset(h, vma, addr);
- struct resv_map *resv = inode->i_mapping->private_data;
-
- return region_chg(resv, idx, idx + 1);
-
- } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
- return 1;
-
- } else {
- long err;
- pgoff_t idx = vma_hugecache_offset(h, vma, addr);
- struct resv_map *resv = vma_resv_map(vma);
-
- err = region_chg(resv, idx, idx + 1);
- if (err < 0)
- return err;
- return 0;
- }
-}
static void vma_commit_reservation(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
@@ -1140,8 +1133,7 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
struct hugepage_subpool *spool = subpool_vma(vma);
struct hstate *h = hstate_vma(vma);
struct page *page;
- long chg;
- int ret, idx;
+ int ret, idx, has_reserve;
struct hugetlb_cgroup *h_cg;

idx = hstate_index(h);
@@ -1153,20 +1145,21 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
* need pages and subpool limit allocated allocated if no reserve
* mapping overlaps.
*/
- chg = vma_needs_reservation(h, vma, addr);
- if (chg < 0)
+ has_reserve = vma_has_reserves(h, vma, addr);
+ if (has_reserve < 0)
return ERR_PTR(-ENOMEM);
- if (chg)
- if (hugepage_subpool_get_pages(spool, chg))
+
+ if (!has_reserve && (hugepage_subpool_get_pages(spool, 1) < 0))
return ERR_PTR(-ENOSPC);

ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
if (ret) {
- hugepage_subpool_put_pages(spool, chg);
+ if (!has_reserve)
+ hugepage_subpool_put_pages(spool, 1);
return ERR_PTR(-ENOSPC);
}
spin_lock(&hugetlb_lock);
- page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, chg);
+ page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
if (!page) {
spin_unlock(&hugetlb_lock);
page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
@@ -1174,7 +1167,8 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
hugetlb_cgroup_uncharge_cgroup(idx,
pages_per_huge_page(h),
h_cg);
- hugepage_subpool_put_pages(spool, chg);
+ if (!has_reserve)
+ hugepage_subpool_put_pages(spool, 1);
return ERR_PTR(-ENOSPC);
}
spin_lock(&hugetlb_lock);
@@ -2769,7 +2763,7 @@ retry:
* the spinlock.
*/
if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED))
- if (vma_needs_reservation(h, vma, address) < 0) {
+ if (vma_has_reserves(h, vma, address) < 0) {
ret = VM_FAULT_OOM;
goto backout_unlocked;
}
@@ -2860,7 +2854,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
* consumed.
*/
if ((flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) {
- if (vma_needs_reservation(h, vma, address) < 0) {
+ if (vma_has_reserves(h, vma, address) < 0) {
ret = VM_FAULT_OOM;
goto out_mutex;
}
--
1.7.9.5


\
 
 \ /
  Last update: 2013-07-29 08:01    [W:0.267 / U:16.664 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site