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authorDavid S. Miller <davem@davemloft.net>2010-04-06 23:53:30 -0700
committerDavid S. Miller <davem@davemloft.net>2010-04-06 23:53:30 -0700
commit4a35ecf8bf1c4b039503fa554100fe85c761de76 (patch)
tree9b75f5d5636004d9a9aa496924377379be09aa1f /mm/page_cgroup.c
parentb4d562e3c3553ac58c7120555c4e4aefbb090a2a (diff)
parentfb9e2d887243499b8d28efcf80821c4f6a092395 (diff)
downloadlwn-4a35ecf8bf1c4b039503fa554100fe85c761de76.tar.gz
lwn-4a35ecf8bf1c4b039503fa554100fe85c761de76.zip
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts: drivers/net/bonding/bond_main.c drivers/net/via-velocity.c drivers/net/wireless/iwlwifi/iwl-agn.c
Diffstat (limited to 'mm/page_cgroup.c')
-rw-r--r--mm/page_cgroup.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 3dd88539a0e6..6c0081441a32 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -284,6 +284,7 @@ static DEFINE_MUTEX(swap_cgroup_mutex);
struct swap_cgroup_ctrl {
struct page **map;
unsigned long length;
+ spinlock_t lock;
};
struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
@@ -353,16 +354,22 @@ unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
struct swap_cgroup_ctrl *ctrl;
struct page *mappage;
struct swap_cgroup *sc;
+ unsigned long flags;
+ unsigned short retval;
ctrl = &swap_cgroup_ctrl[type];
mappage = ctrl->map[idx];
sc = page_address(mappage);
sc += pos;
- if (cmpxchg(&sc->id, old, new) == old)
- return old;
+ spin_lock_irqsave(&ctrl->lock, flags);
+ retval = sc->id;
+ if (retval == old)
+ sc->id = new;
else
- return 0;
+ retval = 0;
+ spin_unlock_irqrestore(&ctrl->lock, flags);
+ return retval;
}
/**
@@ -383,13 +390,17 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
struct page *mappage;
struct swap_cgroup *sc;
unsigned short old;
+ unsigned long flags;
ctrl = &swap_cgroup_ctrl[type];
mappage = ctrl->map[idx];
sc = page_address(mappage);
sc += pos;
- old = xchg(&sc->id, id);
+ spin_lock_irqsave(&ctrl->lock, flags);
+ old = sc->id;
+ sc->id = id;
+ spin_unlock_irqrestore(&ctrl->lock, flags);
return old;
}
@@ -441,6 +452,7 @@ int swap_cgroup_swapon(int type, unsigned long max_pages)
mutex_lock(&swap_cgroup_mutex);
ctrl->length = length;
ctrl->map = array;
+ spin_lock_init(&ctrl->lock);
if (swap_cgroup_prepare(type)) {
/* memory shortage */
ctrl->map = NULL;