diff options
Diffstat (limited to 'include/linux/page_cgroup.h')
| -rw-r--r-- | include/linux/page_cgroup.h | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h index b02195dfc1b..6d6cb7a57bb 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; |