michaelh/zephyr
1
0
Fork 0
Code Releases Activity

kernel: Scheduler rewrite

Browse source 
This replaces the existing scheduler (but not priority handling)
implementation with a somewhat simpler one.  Behavior as to thread
selection does not change.  New features:

+ Unifies SMP and uniprocessing selection code (with the sole
  exception of the "cache" trick not being possible in SMP).

+ The old static multi-queue implementation is gone and has been
  replaced with a build-time choice of either a "dumb" list
  implementation (faster and significantly smaller for apps with only
  a few threads) or a balanced tree queue which scales well to
  arbitrary numbers of threads and priority levels.  This is
  controlled via the CONFIG_SCHED_DUMB kconfig variable.

+ The balanced tree implementation is usable symmetrically for the
  wait_q abstraction, fixing a scalability glitch Zephyr had when many
  threads were waiting on a single object.  This can be selected via
  CONFIG_WAITQ_FAST.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This commit is contained in:
Andy Ross 2018-05-03 14:51:49 -07:00 • committed by Anas Nashif
commit 1acd8c2996
10 changed files with 600 additions and 484 deletions
Download patch file Download diff file Expand all files Collapse all files

33
include/kernel.h
View file

@ -22,6 +22,7 @@
#include <atomic.h>
#include <errno.h>
#include <misc/__assert.h>
#include <sched_priq.h>
#include <misc/dlist.h>
#include <misc/slist.h>
#include <misc/sflist.h>
@ -33,6 +34,7 @@
#include <syscall.h>
#include <misc/printk.h>
#include <arch/cpu.h>
#include <misc/rb.h>
#ifdef __cplusplus
extern "C" {
@ -91,12 +93,26 @@ extern "C" {
#define K_HIGHEST_APPLICATION_THREAD_PRIO (K_HIGHEST_THREAD_PRIO)
#define K_LOWEST_APPLICATION_THREAD_PRIO (K_LOWEST_THREAD_PRIO - 1)
#ifdef CONFIG_WAITQ_FAST
typedef struct {
struct _priq_rb waitq;
} _wait_q_t;
extern int _priq_rb_lessthan(struct rbnode *a, struct rbnode *b);
#define _WAIT_Q_INIT(wait_q) { { { .lessthan_fn = _priq_rb_lessthan } } }
#else
typedef struct {
sys_dlist_t waitq;
} _wait_q_t;
#define _WAIT_Q_INIT(wait_q) { SYS_DLIST_STATIC_INIT(&(wait_q)->waitq) }
#endif
#ifdef CONFIG_OBJECT_TRACING
#define _OBJECT_TRACING_NEXT_PTR(type) struct type *__next
#define _OBJECT_TRACING_INIT .__next = NULL,
@ -405,7 +421,17 @@ struct __thread_entry {
struct _thread_base {
/* this thread's entry in a ready/wait queue */
sys_dnode_t k_q_node;
union {
sys_dlist_t qnode_dlist;
struct rbnode qnode_rb;
};
#ifdef CONFIG_WAITQ_FAST
/* wait queue on which the thread is pended (needed only for
* trees, not dumb lists)
*/
_wait_q_t *pended_on;
#endif
/* user facing 'thread options'; values defined in include/kernel.h */
u8_t user_options;
@ -440,13 +466,12 @@ struct _thread_base {
u16_t preempt;
};
u32_t order_key;
#ifdef CONFIG_SMP
/* True for the per-CPU idle threads */
u8_t is_idle;
/* Non-zero when actively running on a CPU */
u8_t active;
/* CPU index on which thread was last run */
u8_t cpu;