diff options
Diffstat (limited to 'ANDROID_3.4.5/include/linux/dynamic_queue_limits.h')
-rw-r--r-- | ANDROID_3.4.5/include/linux/dynamic_queue_limits.h | 97 |
1 files changed, 0 insertions, 97 deletions
diff --git a/ANDROID_3.4.5/include/linux/dynamic_queue_limits.h b/ANDROID_3.4.5/include/linux/dynamic_queue_limits.h deleted file mode 100644 index 5621547d..00000000 --- a/ANDROID_3.4.5/include/linux/dynamic_queue_limits.h +++ /dev/null @@ -1,97 +0,0 @@ -/* - * Dynamic queue limits (dql) - Definitions - * - * Copyright (c) 2011, Tom Herbert <therbert@google.com> - * - * This header file contains the definitions for dynamic queue limits (dql). - * dql would be used in conjunction with a producer/consumer type queue - * (possibly a HW queue). Such a queue would have these general properties: - * - * 1) Objects are queued up to some limit specified as number of objects. - * 2) Periodically a completion process executes which retires consumed - * objects. - * 3) Starvation occurs when limit has been reached, all queued data has - * actually been consumed, but completion processing has not yet run - * so queuing new data is blocked. - * 4) Minimizing the amount of queued data is desirable. - * - * The goal of dql is to calculate the limit as the minimum number of objects - * needed to prevent starvation. - * - * The primary functions of dql are: - * dql_queued - called when objects are enqueued to record number of objects - * dql_avail - returns how many objects are available to be queued based - * on the object limit and how many objects are already enqueued - * dql_completed - called at completion time to indicate how many objects - * were retired from the queue - * - * The dql implementation does not implement any locking for the dql data - * structures, the higher layer should provide this. dql_queued should - * be serialized to prevent concurrent execution of the function; this - * is also true for dql_completed. However, dql_queued and dlq_completed can - * be executed concurrently (i.e. they can be protected by different locks). - */ - -#ifndef _LINUX_DQL_H -#define _LINUX_DQL_H - -#ifdef __KERNEL__ - -struct dql { - /* Fields accessed in enqueue path (dql_queued) */ - unsigned int num_queued; /* Total ever queued */ - unsigned int adj_limit; /* limit + num_completed */ - unsigned int last_obj_cnt; /* Count at last queuing */ - - /* Fields accessed only by completion path (dql_completed) */ - - unsigned int limit ____cacheline_aligned_in_smp; /* Current limit */ - unsigned int num_completed; /* Total ever completed */ - - unsigned int prev_ovlimit; /* Previous over limit */ - unsigned int prev_num_queued; /* Previous queue total */ - unsigned int prev_last_obj_cnt; /* Previous queuing cnt */ - - unsigned int lowest_slack; /* Lowest slack found */ - unsigned long slack_start_time; /* Time slacks seen */ - - /* Configuration */ - unsigned int max_limit; /* Max limit */ - unsigned int min_limit; /* Minimum limit */ - unsigned int slack_hold_time; /* Time to measure slack */ -}; - -/* Set some static maximums */ -#define DQL_MAX_OBJECT (UINT_MAX / 16) -#define DQL_MAX_LIMIT ((UINT_MAX / 2) - DQL_MAX_OBJECT) - -/* - * Record number of objects queued. Assumes that caller has already checked - * availability in the queue with dql_avail. - */ -static inline void dql_queued(struct dql *dql, unsigned int count) -{ - BUG_ON(count > DQL_MAX_OBJECT); - - dql->num_queued += count; - dql->last_obj_cnt = count; -} - -/* Returns how many objects can be queued, < 0 indicates over limit. */ -static inline int dql_avail(const struct dql *dql) -{ - return dql->adj_limit - dql->num_queued; -} - -/* Record number of completed objects and recalculate the limit. */ -void dql_completed(struct dql *dql, unsigned int count); - -/* Reset dql state */ -void dql_reset(struct dql *dql); - -/* Initialize dql state */ -int dql_init(struct dql *dql, unsigned hold_time); - -#endif /* _KERNEL_ */ - -#endif /* _LINUX_DQL_H */ |