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author | David S. Miller <davem@davemloft.net> | 2010-04-06 23:53:30 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2010-04-06 23:53:30 -0700 |
commit | 4a35ecf8bf1c4b039503fa554100fe85c761de76 (patch) | |
tree | 9b75f5d5636004d9a9aa496924377379be09aa1f /mm/page_cgroup.c | |
parent | b4d562e3c3553ac58c7120555c4e4aefbb090a2a (diff) | |
parent | fb9e2d887243499b8d28efcf80821c4f6a092395 (diff) | |
download | lwn-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.c | 20 |
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; |