summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--include/linux/memcontrol.h20
-rw-r--r--mm/filemap.c12
-rw-r--r--mm/memcontrol.c166
-rw-r--r--mm/memory.c47
-rw-r--r--mm/migrate.c6
-rw-r--r--mm/page_alloc.c3
-rw-r--r--mm/rmap.c17
-rw-r--r--mm/swap_state.c10
-rw-r--r--mm/swapfile.c41
9 files changed, 295 insertions, 27 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 7d1f119..f5b47ef 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -30,6 +30,13 @@ extern void mm_free_cgroup(struct mm_struct *mm);
extern void page_assign_page_cgroup(struct page *page,
struct page_cgroup *pc);
extern struct page_cgroup *page_get_page_cgroup(struct page *page);
+extern int mem_cgroup_charge(struct page *page, struct mm_struct *mm);
+extern void mem_cgroup_uncharge(struct page_cgroup *pc);
+
+static inline void mem_cgroup_uncharge_page(struct page *page)
+{
+ mem_cgroup_uncharge(page_get_page_cgroup(page));
+}
#else /* CONFIG_CGROUP_MEM_CONT */
static inline void mm_init_cgroup(struct mm_struct *mm,
@@ -51,6 +58,19 @@ static inline struct page_cgroup *page_get_page_cgroup(struct page *page)
return NULL;
}
+static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm)
+{
+ return 0;
+}
+
+static inline void mem_cgroup_uncharge(struct page_cgroup *pc)
+{
+}
+
+static inline void mem_cgroup_uncharge_page(struct page *page)
+{
+}
+
#endif /* CONFIG_CGROUP_MEM_CONT */
#endif /* _LINUX_MEMCONTROL_H */
diff --git a/mm/filemap.c b/mm/filemap.c
index 81fb9bf..b7a01e9 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -33,6 +33,7 @@
#include <linux/syscalls.h>
#include <linux/cpuset.h>
#include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
+#include <linux/memcontrol.h>
#include "internal.h"
/*
@@ -118,6 +119,7 @@ void __remove_from_page_cache(struct page *page)
{
struct address_space *mapping = page->mapping;
+ mem_cgroup_uncharge_page(page);
radix_tree_delete(&mapping->page_tree, page->index);
page->mapping = NULL;
mapping->nrpages--;
@@ -461,6 +463,11 @@ int add_to_page_cache(struct page *page, struct address_space *mapping,
int error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
if (error == 0) {
+
+ error = mem_cgroup_charge(page, current->mm);
+ if (error)
+ goto out;
+
write_lock_irq(&mapping->tree_lock);
error = radix_tree_insert(&mapping->page_tree, offset, page);
if (!error) {
@@ -470,10 +477,13 @@ int add_to_page_cache(struct page *page, struct address_space *mapping,
page->index = offset;
mapping->nrpages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
- }
+ } else
+ mem_cgroup_uncharge_page(page);
+
write_unlock_irq(&mapping->tree_lock);
radix_tree_preload_end();
}
+out:
return error;
}
EXPORT_SYMBOL(add_to_page_cache);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4d4805e..ebca767 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -21,6 +21,9 @@
#include <linux/memcontrol.h>
#include <linux/cgroup.h>
#include <linux/mm.h>
+#include <linux/page-flags.h>
+#include <linux/bit_spinlock.h>
+#include <linux/rcupdate.h>
struct cgroup_subsys mem_cgroup_subsys;
@@ -31,7 +34,9 @@ struct cgroup_subsys mem_cgroup_subsys;
* to help the administrator determine what knobs to tune.
*
* TODO: Add a water mark for the memory controller. Reclaim will begin when
- * we hit the water mark.
+ * we hit the water mark. May be even add a low water mark, such that
+ * no reclaim occurs from a cgroup at it's low water mark, this is
+ * a feature that will be implemented much later in the future.
*/
struct mem_cgroup {
struct cgroup_subsys_state css;
@@ -49,6 +54,14 @@ struct mem_cgroup {
};
/*
+ * We use the lower bit of the page->page_cgroup pointer as a bit spin
+ * lock. We need to ensure that page->page_cgroup is atleast two
+ * byte aligned (based on comments from Nick Piggin)
+ */
+#define PAGE_CGROUP_LOCK_BIT 0x0
+#define PAGE_CGROUP_LOCK (1 << PAGE_CGROUP_LOCK_BIT)
+
+/*
* A page_cgroup page is associated with every page descriptor. The
* page_cgroup helps us identify information about the cgroup
*/
@@ -56,6 +69,8 @@ struct page_cgroup {
struct list_head lru; /* per cgroup LRU list */
struct page *page;
struct mem_cgroup *mem_cgroup;
+ atomic_t ref_cnt; /* Helpful when pages move b/w */
+ /* mapped and cached states */
};
@@ -88,14 +103,157 @@ void mm_free_cgroup(struct mm_struct *mm)
css_put(&mm->mem_cgroup->css);
}
+static inline int page_cgroup_locked(struct page *page)
+{
+ return bit_spin_is_locked(PAGE_CGROUP_LOCK_BIT,
+ &page->page_cgroup);
+}
+
void page_assign_page_cgroup(struct page *page, struct page_cgroup *pc)
{
- page->page_cgroup = (unsigned long)pc;
+ int locked;
+
+ /*
+ * While resetting the page_cgroup we might not hold the
+ * page_cgroup lock. free_hot_cold_page() is an example
+ * of such a scenario
+ */
+ if (pc)
+ VM_BUG_ON(!page_cgroup_locked(page));
+ locked = (page->page_cgroup & PAGE_CGROUP_LOCK);
+ page->page_cgroup = ((unsigned long)pc | locked);
}
struct page_cgroup *page_get_page_cgroup(struct page *page)
{
- return page->page_cgroup;
+ return (struct page_cgroup *)
+ (page->page_cgroup & ~PAGE_CGROUP_LOCK);
+}
+
+void __always_inline lock_page_cgroup(struct page *page)
+{
+ bit_spin_lock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
+ VM_BUG_ON(!page_cgroup_locked(page));
+}
+
+void __always_inline unlock_page_cgroup(struct page *page)
+{
+ bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);
+}
+
+/*
+ * Charge the memory controller for page usage.
+ * Return
+ * 0 if the charge was successful
+ * < 0 if the cgroup is over its limit
+ */
+int mem_cgroup_charge(struct page *page, struct mm_struct *mm)
+{
+ struct mem_cgroup *mem;
+ struct page_cgroup *pc, *race_pc;
+
+ /*
+ * Should page_cgroup's go to their own slab?
+ * One could optimize the performance of the charging routine
+ * by saving a bit in the page_flags and using it as a lock
+ * to see if the cgroup page already has a page_cgroup associated
+ * with it
+ */
+ lock_page_cgroup(page);
+ pc = page_get_page_cgroup(page);
+ /*
+ * The page_cgroup exists and the page has already been accounted
+ */
+ if (pc) {
+ atomic_inc(&pc->ref_cnt);
+ goto done;
+ }
+
+ unlock_page_cgroup(page);
+
+ pc = kzalloc(sizeof(struct page_cgroup), GFP_KERNEL);
+ if (pc == NULL)
+ goto err;
+
+ rcu_read_lock();
+ /*
+ * We always charge the cgroup the mm_struct belongs to
+ * the mm_struct's mem_cgroup changes on task migration if the
+ * thread group leader migrates. It's possible that mm is not
+ * set, if so charge the init_mm (happens for pagecache usage).
+ */
+ if (!mm)
+ mm = &init_mm;
+
+ mem = rcu_dereference(mm->mem_cgroup);
+ /*
+ * For every charge from the cgroup, increment reference
+ * count
+ */
+ css_get(&mem->css);
+ rcu_read_unlock();
+
+ /*
+ * If we created the page_cgroup, we should free it on exceeding
+ * the cgroup limit.
+ */
+ if (res_counter_charge(&mem->res, 1)) {
+ css_put(&mem->css);
+ goto free_pc;
+ }
+
+ lock_page_cgroup(page);
+ /*
+ * Check if somebody else beat us to allocating the page_cgroup
+ */
+ race_pc = page_get_page_cgroup(page);
+ if (race_pc) {
+ kfree(pc);
+ pc = race_pc;
+ atomic_inc(&pc->ref_cnt);
+ res_counter_uncharge(&mem->res, 1);
+ css_put(&mem->css);
+ goto done;
+ }
+
+ atomic_set(&pc->ref_cnt, 1);
+ pc->mem_cgroup = mem;
+ pc->page = page;
+ page_assign_page_cgroup(page, pc);
+
+done:
+ unlock_page_cgroup(page);
+ return 0;
+free_pc:
+ kfree(pc);
+ return -ENOMEM;
+err:
+ unlock_page_cgroup(page);
+ return -ENOMEM;
+}
+
+/*
+ * Uncharging is always a welcome operation, we never complain, simply
+ * uncharge.
+ */
+void mem_cgroup_uncharge(struct page_cgroup *pc)
+{
+ struct mem_cgroup *mem;
+ struct page *page;
+
+ if (!pc)
+ return;
+
+ if (atomic_dec_and_test(&pc->ref_cnt)) {
+ page = pc->page;
+ lock_page_cgroup(page);
+ mem = pc->mem_cgroup;
+ css_put(&mem->css);
+ page_assign_page_cgroup(page, NULL);
+ unlock_page_cgroup(page);
+ res_counter_uncharge(&mem->res, 1);
+ kfree(pc);
+ }
}
static ssize_t mem_cgroup_read(struct cgroup *cont, struct cftype *cft,
@@ -150,6 +308,8 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
return NULL;
res_counter_init(&mem->res);
+ INIT_LIST_HEAD(&mem->active_list);
+ INIT_LIST_HEAD(&mem->inactive_list);
return &mem->css;
}
diff --git a/mm/memory.c b/mm/memory.c
index 9d073fa..0ba224e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -50,6 +50,7 @@
#include <linux/delayacct.h>
#include <linux/init.h>
#include <linux/writeback.h>
+#include <linux/memcontrol.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
@@ -1144,16 +1145,20 @@ static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *pa
{
int retval;
pte_t *pte;
- spinlock_t *ptl;
+ spinlock_t *ptl;
+
+ retval = mem_cgroup_charge(page, mm);
+ if (retval)
+ goto out;
retval = -EINVAL;
if (PageAnon(page))
- goto out;
+ goto out_uncharge;
retval = -ENOMEM;
flush_dcache_page(page);
pte = get_locked_pte(mm, addr, &ptl);
if (!pte)
- goto out;
+ goto out_uncharge;
retval = -EBUSY;
if (!pte_none(*pte))
goto out_unlock;
@@ -1165,8 +1170,12 @@ static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *pa
set_pte_at(mm, addr, pte, mk_pte(page, prot));
retval = 0;
+ pte_unmap_unlock(pte, ptl);
+ return retval;
out_unlock:
pte_unmap_unlock(pte, ptl);
+out_uncharge:
+ mem_cgroup_uncharge_page(page);
out:
return retval;
}
@@ -1641,6 +1650,9 @@ gotten:
cow_user_page(new_page, old_page, address, vma);
__SetPageUptodate(new_page);
+ if (mem_cgroup_charge(new_page, mm))
+ goto oom_free_new;
+
/*
* Re-check the pte - we dropped the lock
*/
@@ -1672,7 +1684,9 @@ gotten:
/* Free the old page.. */
new_page = old_page;
ret |= VM_FAULT_WRITE;
- }
+ } else
+ mem_cgroup_uncharge_page(new_page);
+
if (new_page)
page_cache_release(new_page);
if (old_page)
@@ -1696,6 +1710,8 @@ unlock:
put_page(dirty_page);
}
return ret;
+oom_free_new:
+ __free_page(new_page);
oom:
if (old_page)
page_cache_release(old_page);
@@ -2036,6 +2052,12 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
count_vm_event(PGMAJFAULT);
}
+ if (mem_cgroup_charge(page, mm)) {
+ delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ ret = VM_FAULT_OOM;
+ goto out;
+ }
+
mark_page_accessed(page);
lock_page(page);
delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
@@ -2073,8 +2095,10 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (write_access) {
/* XXX: We could OR the do_wp_page code with this one? */
if (do_wp_page(mm, vma, address,
- page_table, pmd, ptl, pte) & VM_FAULT_OOM)
+ page_table, pmd, ptl, pte) & VM_FAULT_OOM) {
+ mem_cgroup_uncharge_page(page);
ret = VM_FAULT_OOM;
+ }
goto out;
}
@@ -2085,6 +2109,7 @@ unlock:
out:
return ret;
out_nomap:
+ mem_cgroup_uncharge_page(page);
pte_unmap_unlock(page_table, ptl);
unlock_page(page);
page_cache_release(page);
@@ -2114,6 +2139,9 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
goto oom;
__SetPageUptodate(page);
+ if (mem_cgroup_charge(page, mm))
+ goto oom_free_page;
+
entry = mk_pte(page, vma->vm_page_prot);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
@@ -2131,8 +2159,11 @@ unlock:
pte_unmap_unlock(page_table, ptl);
return 0;
release:
+ mem_cgroup_uncharge_page(page);
page_cache_release(page);
goto unlock;
+oom_free_page:
+ __free_page(page);
oom:
return VM_FAULT_OOM;
}
@@ -2246,6 +2277,11 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
}
+ if (mem_cgroup_charge(page, mm)) {
+ ret = VM_FAULT_OOM;
+ goto out;
+ }
+
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
/*
@@ -2281,6 +2317,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
/* no need to invalidate: a not-present page won't be cached */
update_mmu_cache(vma, address, entry);
} else {
+ mem_cgroup_uncharge_page(page);
if (anon)
page_cache_release(page);
else
diff --git a/mm/migrate.c b/mm/migrate.c
index 857a987..417bbda 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -29,6 +29,7 @@
#include <linux/mempolicy.h>
#include <linux/vmalloc.h>
#include <linux/security.h>
+#include <linux/memcontrol.h>
#include "internal.h"
@@ -152,6 +153,11 @@ static void remove_migration_pte(struct vm_area_struct *vma,
return;
}
+ if (mem_cgroup_charge(new, mm)) {
+ pte_unmap(ptep);
+ return;
+ }
+
ptl = pte_lockptr(mm, pmd);
spin_lock(ptl);
pte = *ptep;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 37576b8..26a54a1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -43,6 +43,7 @@
#include <linux/backing-dev.h>
#include <linux/fault-inject.h>
#include <linux/page-isolation.h>
+#include <linux/memcontrol.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
@@ -987,6 +988,7 @@ static void free_hot_cold_page(struct page *page, int cold)
if (!PageHighMem(page))
debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
+ VM_BUG_ON(page_get_page_cgroup(page));
arch_free_page(page, 0);
kernel_map_pages(page, 1, 0);
@@ -2525,6 +2527,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
set_page_links(page, zone, nid, pfn);
init_page_count(page);
reset_page_mapcount(page);
+ page_assign_page_cgroup(page, NULL);
SetPageReserved(page);
/*
diff --git a/mm/rmap.c b/mm/rmap.c
index 57ad276..4a34879 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -48,6 +48,7 @@
#include <linux/rcupdate.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
+#include <linux/memcontrol.h>
#include <asm/tlbflush.h>
@@ -554,8 +555,14 @@ void page_add_anon_rmap(struct page *page,
VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
if (atomic_inc_and_test(&page->_mapcount))
__page_set_anon_rmap(page, vma, address);
- else
+ else {
__page_check_anon_rmap(page, vma, address);
+ /*
+ * We unconditionally charged during prepare, we uncharge here
+ * This takes care of balancing the reference counts
+ */
+ mem_cgroup_uncharge_page(page);
+ }
}
/*
@@ -586,6 +593,12 @@ void page_add_file_rmap(struct page *page)
{
if (atomic_inc_and_test(&page->_mapcount))
__inc_zone_page_state(page, NR_FILE_MAPPED);
+ else
+ /*
+ * We unconditionally charged during prepare, we uncharge here
+ * This takes care of balancing the reference counts
+ */
+ mem_cgroup_uncharge_page(page);
}
#ifdef CONFIG_DEBUG_VM
@@ -646,6 +659,8 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma)
page_clear_dirty(page);
set_page_dirty(page);
}
+ mem_cgroup_uncharge_page(page);
+
__dec_zone_page_state(page,
PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
}
diff --git a/mm/swap_state.c b/mm/swap_state.c
index ec42f01..f96e3ff 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -17,6 +17,7 @@
#include <linux/backing-dev.h>
#include <linux/pagevec.h>
#include <linux/migrate.h>
+#include <linux/memcontrol.h>
#include <asm/pgtable.h>
@@ -76,6 +77,11 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
BUG_ON(PagePrivate(page));
error = radix_tree_preload(gfp_mask);
if (!error) {
+
+ error = mem_cgroup_charge(page, current->mm);
+ if (error)
+ goto out;
+
write_lock_irq(&swapper_space.tree_lock);
error = radix_tree_insert(&swapper_space.page_tree,
entry.val, page);
@@ -86,10 +92,13 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
total_swapcache_pages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
INC_CACHE_INFO(add_total);
+ } else {
+ mem_cgroup_uncharge_page(page);
}
write_unlock_irq(&swapper_space.tree_lock);
radix_tree_preload_end();
}
+out:
return error;
}
@@ -104,6 +113,7 @@ void __delete_from_swap_cache(struct page *page)
BUG_ON(PageWriteback(page));
BUG_ON(PagePrivate(page));
+ mem_cgroup_uncharge_page(page);
radix_tree_delete(&swapper_space.page_tree, page_private(page));
set_page_private(page, 0);
ClearPageSwapCache(page);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index afae7b1..fddc4cc 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -27,6 +27,7 @@
#include <linux/mutex.h>
#include <linux/capability.h>
#include <linux/syscalls.h>
+#include <linux/memcontrol.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
@@ -506,9 +507,12 @@ unsigned int count_swap_pages(int type, int free)
* just let do_wp_page work it out if a write is requested later - to
* force COW, vm_page_prot omits write permission from any private vma.
*/
-static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
+static int unuse_pte(struct vm_area_struct *vma, pte_t *pte,
unsigned long addr, swp_entry_t entry, struct page *page)
{
+ if (mem_cgroup_charge(page, vma->vm_mm))
+ return -ENOMEM;
+
inc_mm_counter(vma->vm_mm, anon_rss);
get_page(page);
set_pte_at(vma->vm_mm, addr, pte,
@@ -520,6 +524,7 @@ static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
* immediately swapped out again after swapon.
*/
activate_page(page);
+ return 1;
}
static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
@@ -529,7 +534,7 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
pte_t swp_pte = swp_entry_to_pte(entry);
pte_t *pte;
spinlock_t *ptl;
- int found = 0;
+ int ret = 0;
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
do {
@@ -538,13 +543,12 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
* Test inline before going to call unuse_pte.
*/
if (unlikely(pte_same(*pte, swp_pte))) {
- unuse_pte(vma, pte++, addr, entry, page);
- found = 1;
+ ret = unuse_pte(vma, pte++, addr, entry, page);
break;
}
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap_unlock(pte - 1, ptl);
- return found;
+ return ret;
}
static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
@@ -553,14 +557,16 @@ static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
{
pmd_t *pmd;
unsigned long next;
+ int ret;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none_or_clear_bad(pmd))
continue;
- if (unuse_pte_range(vma, pmd, addr, next, entry, page))
- return 1;
+ ret = unuse_pte_range(vma, pmd, addr, next, entry, page);
+ if (ret)
+ return ret;
} while (pmd++, addr = next, addr != end);
return 0;
}
@@ -571,14 +577,16 @@ static inline int unuse_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
{
pud_t *pud;
unsigned long next;
+ int ret;
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
- if (unuse_pmd_range(vma, pud, addr, next, entry, page))
- return 1;
+ ret = unuse_pmd_range(vma, pud, addr, next, entry, page);
+ if (ret)
+ return ret;
} while (pud++, addr = next, addr != end);
return 0;
}
@@ -588,6 +596,7 @@ static int unuse_vma(struct vm_area_struct *vma,
{
pgd_t *pgd;
unsigned long addr, end, next;
+ int ret;
if (page->mapping) {
addr = page_address_in_vma(page, vma);
@@ -605,8 +614,9 @@ static int unuse_vma(struct vm_area_struct *vma,
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
- if (unuse_pud_range(vma, pgd, addr, next, entry, page))
- return 1;
+ ret = unuse_pud_range(vma, pgd, addr, next, entry, page);
+ if (ret)
+ return ret;
} while (pgd++, addr = next, addr != end);
return 0;
}
@@ -615,6 +625,7 @@ static int unuse_mm(struct mm_struct *mm,
swp_entry_t entry, struct page *page)
{
struct vm_area_struct *vma;
+ int ret = 0;
if (!down_read_trylock(&mm->mmap_sem)) {
/*
@@ -627,15 +638,11 @@ static int unuse_mm(struct mm_struct *mm,
lock_page(page);
}
for (vma = mm->mmap; vma; vma = vma->vm_next) {
- if (vma->anon_vma && unuse_vma(vma, entry, page))
+ if (vma->anon_vma && (ret = unuse_vma(vma, entry, page)))
break;
}
up_read(&mm->mmap_sem);
- /*
- * Currently unuse_mm cannot fail, but leave error handling
- * at call sites for now, since we change it from time to time.
- */
- return 0;
+ return (ret < 0)? ret: 0;
}
/*
OpenPOWER on IntegriCloud