diff options
Diffstat (limited to 'include/linux/res_counter.h')
| -rw-r--r-- | include/linux/res_counter.h | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h index 56b7bc32db4f..b810855024f9 100644 --- a/include/linux/res_counter.h +++ b/include/linux/res_counter.h @@ -40,6 +40,11 @@ struct res_counter { */ unsigned long long soft_limit; /* + * the limit under which the usage cannot be pushed + * due to external pressure. + */ + unsigned long long low_limit; + /* * the number of unsuccessful attempts to consume the resource */ unsigned long long failcnt; @@ -88,6 +93,7 @@ enum { RES_LIMIT, RES_FAILCNT, RES_SOFT_LIMIT, + RES_LOW_LIMIT, }; /* @@ -175,6 +181,28 @@ res_counter_soft_limit_excess(struct res_counter *cnt) return excess; } +/** + * Get the difference between the usage and the low limit + * @cnt: The counter + * + * Returns 0 if usage is less than or equal to low limit + * The difference between usage and low limit, otherwise. + */ +static inline unsigned long long +res_counter_low_limit_excess(struct res_counter *cnt) +{ + unsigned long long excess; + unsigned long flags; + + spin_lock_irqsave(&cnt->lock, flags); + if (cnt->usage <= cnt->low_limit) + excess = 0; + else + excess = cnt->usage - cnt->low_limit; + spin_unlock_irqrestore(&cnt->lock, flags); + return excess; +} + static inline void res_counter_reset_max(struct res_counter *cnt) { unsigned long flags; @@ -220,4 +248,16 @@ res_counter_set_soft_limit(struct res_counter *cnt, return 0; } +static inline int +res_counter_set_low_limit(struct res_counter *cnt, + unsigned long long low_limit) +{ + unsigned long flags; + + spin_lock_irqsave(&cnt->lock, flags); + cnt->low_limit = low_limit; + spin_unlock_irqrestore(&cnt->lock, flags); + return 0; +} + #endif |