michaelh/zephyr
1
0
Fork 0
Code Releases Activity

kernel: Add the old "multi queue" scheduler algorithm as an option

Browse source 
Zephyr 1.12 removed the old scheduler and replaced it with the choice
of a "dumb" list or a balanced tree.  But the old multi-queue
algorithm is still useful in the space between these two (applications
with large-ish numbers of runnable threads, but that don't need fancy
features like EDF or SMP affinity).  So add it as a
CONFIG_SCHED_MULTIQ option.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This commit is contained in:
Andy Ross 2018-06-28 10:38:14 -07:00 • committed by Anas Nashif
commit 9f06a35450
5 changed files with 106 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

16
include/sched_priq.h
View file

@ -44,4 +44,20 @@ void _priq_rb_add(struct _priq_rb *pq, struct k_thread *thread);
void _priq_rb_remove(struct _priq_rb *pq, struct k_thread *thread);
struct k_thread *_priq_rb_best(struct _priq_rb *pq);
/* Traditional/textbook "multi-queue" structure. Separate lists for a
* small number (max 32 here) of fixed priorities. This corresponds
* to the original Zephyr scheduler. RAM requirements are
* comparatively high, but performance is very fast. Won't work with
* features like deadline scheduling which need large priority spaces
* to represet their requirements.
*/
struct _priq_mq {
sys_dlist_t queues[32];
unsigned int bitmask; /* bit 1<<i set if queues[i] is non-empty */
};
void _priq_mq_add(struct _priq_mq *pq, struct k_thread *thread);
void _priq_mq_remove(struct _priq_mq *pq, struct k_thread *thread);
struct k_thread *_priq_mq_best(struct _priq_mq *pq);
#endif /* _sched_priq__h_ */