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Diffstat (limited to 'mm/swap_cgroup.c')
-rw-r--r--mm/swap_cgroup.c40
1 files changed, 30 insertions, 10 deletions
diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c
index 3405b4ee1757..fcd2740f4ed7 100644
--- a/mm/swap_cgroup.c
+++ b/mm/swap_cgroup.c
@@ -61,21 +61,27 @@ not_enough_page:
return -ENOMEM;
}
+static struct swap_cgroup *__lookup_swap_cgroup(struct swap_cgroup_ctrl *ctrl,
+ pgoff_t offset)
+{
+ struct page *mappage;
+ struct swap_cgroup *sc;
+
+ mappage = ctrl->map[offset / SC_PER_PAGE];
+ sc = page_address(mappage);
+ return sc + offset % SC_PER_PAGE;
+}
+
static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
struct swap_cgroup_ctrl **ctrlp)
{
pgoff_t offset = swp_offset(ent);
struct swap_cgroup_ctrl *ctrl;
- struct page *mappage;
- struct swap_cgroup *sc;
ctrl = &swap_cgroup_ctrl[swp_type(ent)];
if (ctrlp)
*ctrlp = ctrl;
-
- mappage = ctrl->map[offset / SC_PER_PAGE];
- sc = page_address(mappage);
- return sc + offset % SC_PER_PAGE;
+ return __lookup_swap_cgroup(ctrl, offset);
}
/**
@@ -108,25 +114,39 @@ unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
}
/**
- * swap_cgroup_record - record mem_cgroup for this swp_entry.
- * @ent: swap entry to be recorded into
+ * swap_cgroup_record - record mem_cgroup for a set of swap entries
+ * @ent: the first swap entry to be recorded into
* @id: mem_cgroup to be recorded
+ * @nr_ents: number of swap entries to be recorded
*
* Returns old value at success, 0 at failure.
* (Of course, old value can be 0.)
*/
-unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
+unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id,
+ unsigned int nr_ents)
{
struct swap_cgroup_ctrl *ctrl;
struct swap_cgroup *sc;
unsigned short old;
unsigned long flags;
+ pgoff_t offset = swp_offset(ent);
+ pgoff_t end = offset + nr_ents;
sc = lookup_swap_cgroup(ent, &ctrl);
spin_lock_irqsave(&ctrl->lock, flags);
old = sc->id;
- sc->id = id;
+ for (;;) {
+ VM_BUG_ON(sc->id != old);
+ sc->id = id;
+ offset++;
+ if (offset == end)
+ break;
+ if (offset % SC_PER_PAGE)
+ sc++;
+ else
+ sc = __lookup_swap_cgroup(ctrl, offset);
+ }
spin_unlock_irqrestore(&ctrl->lock, flags);
return old;