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Diffstat (limited to 'include/linux/page_cgroup.h')
-rw-r--r--include/linux/page_cgroup.h31
1 files changed, 28 insertions, 3 deletions
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index b02195dfc1b0..6d6cb7a57bb3 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -35,12 +35,15 @@ struct page_cgroup *lookup_page_cgroup(struct page *page);
enum {
/* flags for mem_cgroup */
- PCG_LOCK, /* page cgroup is locked */
+ PCG_LOCK, /* Lock for pc->mem_cgroup and following bits. */
PCG_CACHE, /* charged as cache */
PCG_USED, /* this object is in use. */
- PCG_ACCT_LRU, /* page has been accounted for */
- PCG_FILE_MAPPED, /* page is accounted as "mapped" */
PCG_MIGRATION, /* under page migration */
+ /* flags for mem_cgroup and file and I/O status */
+ PCG_MOVE_LOCK, /* For race between move_account v.s. following bits */
+ PCG_FILE_MAPPED, /* page is accounted as "mapped" */
+ /* No lock in page_cgroup */
+ PCG_ACCT_LRU, /* page has been accounted for (under lru_lock) */
};
#define TESTPCGFLAG(uname, lname) \
@@ -94,6 +97,10 @@ static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
static inline void lock_page_cgroup(struct page_cgroup *pc)
{
+ /*
+ * Don't take this lock in IRQ context.
+ * This lock is for pc->mem_cgroup, USED, CACHE, MIGRATION
+ */
bit_spin_lock(PCG_LOCK, &pc->flags);
}
@@ -107,6 +114,24 @@ static inline int page_is_cgroup_locked(struct page_cgroup *pc)
return bit_spin_is_locked(PCG_LOCK, &pc->flags);
}
+static inline void move_lock_page_cgroup(struct page_cgroup *pc,
+ unsigned long *flags)
+{
+ /*
+ * We know updates to pc->flags of page cache's stats are from both of
+ * usual context or IRQ context. Disable IRQ to avoid deadlock.
+ */
+ local_irq_save(*flags);
+ bit_spin_lock(PCG_MOVE_LOCK, &pc->flags);
+}
+
+static inline void move_unlock_page_cgroup(struct page_cgroup *pc,
+ unsigned long *flags)
+{
+ bit_spin_unlock(PCG_MOVE_LOCK, &pc->flags);
+ local_irq_restore(*flags);
+}
+
#else /* CONFIG_CGROUP_MEM_RES_CTLR */
struct page_cgroup;