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kernel: priority queues: declare as static inlines

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After the move to C files we got some drop in the performance when
running latency_measure. This patch declares the priority queue
functions as static inlines with minor optimizations.

The result for one metric (on qemu):

3.6 and before the anything was changed:

  Get data from LIFO (w/ ctx switch): 13087 ns

after original change (46484da502):

  Get data from LIFO (w/ ctx switch): 13663 ns

with this change:

  Get data from LIFO (w/ ctx switch): 12543 ns

So overall, a net gain of ~ 500ns that can be seen across the board on many
of the metrics.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This commit is contained in:
Anas Nashif 2024-04-11 11:59:07 -04:00
parent 0b8714bcde
commit 4593f0d71c
3 changed files with 141 additions and 148 deletions
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155
kernel/include/priority_q.h
View file

@ -7,13 +7,20 @@
#ifndef ZEPHYR_KERNEL_INCLUDE_PRIORITY_Q_H_ #ifndef ZEPHYR_KERNEL_INCLUDE_PRIORITY_Q_H_
#define ZEPHYR_KERNEL_INCLUDE_PRIORITY_Q_H_ #define ZEPHYR_KERNEL_INCLUDE_PRIORITY_Q_H_
#include <zephyr/sys/math_extras.h>
#include <zephyr/sys/dlist.h>
/* Dump Scheduling */ extern int32_t z_sched_prio_cmp(struct k_thread *thread_1,
struct k_thread *thread_2);
bool z_priq_rb_lessthan(struct rbnode *a, struct rbnode *b);
/* Dumb Scheduling */
#if defined(CONFIG_SCHED_DUMB) #if defined(CONFIG_SCHED_DUMB)
#define _priq_run_add z_priq_dumb_add #define _priq_run_add z_priq_dumb_add
#define _priq_run_remove z_priq_dumb_remove #define _priq_run_remove z_priq_dumb_remove
# if defined(CONFIG_SCHED_CPU_MASK) # if defined(CONFIG_SCHED_CPU_MASK)
# define _priq_run_best _priq_dumb_mask_best # define _priq_run_best z_priq_dumb_mask_best
# else # else
# define _priq_run_best z_priq_dumb_best # define _priq_run_best z_priq_dumb_best
# endif /* CONFIG_SCHED_CPU_MASK */ # endif /* CONFIG_SCHED_CPU_MASK */
@ -25,11 +32,11 @@
/* Multi Queue Scheduling */ /* Multi Queue Scheduling */
#elif defined(CONFIG_SCHED_MULTIQ) #elif defined(CONFIG_SCHED_MULTIQ)
# if defined(CONFIG_64BIT) #if defined(CONFIG_64BIT)
# define NBITS 64 #define NBITS 64
# else #else
# define NBITS 32 #define NBITS 32
# endif #endif /* CONFIG_64BIT */
#define _priq_run_add z_priq_mq_add #define _priq_run_add z_priq_mq_add
#define _priq_run_remove z_priq_mq_remove #define _priq_run_remove z_priq_mq_remove
@ -40,30 +47,99 @@ static ALWAYS_INLINE void z_priq_mq_remove(struct _priq_mq *pq, struct k_thread
/* Scalable Wait Queue */ /* Scalable Wait Queue */
#if defined(CONFIG_WAITQ_SCALABLE) #if defined(CONFIG_WAITQ_SCALABLE)
#define z_priq_wait_add z_priq_rb_add #define _priq_wait_add z_priq_rb_add
#define _priq_wait_remove z_priq_rb_remove #define _priq_wait_remove z_priq_rb_remove
#define _priq_wait_best z_priq_rb_best #define _priq_wait_best z_priq_rb_best
/* Dump Wait Queue */ /* Dumb Wait Queue */
#elif defined(CONFIG_WAITQ_DUMB) #elif defined(CONFIG_WAITQ_DUMB)
#define z_priq_wait_add z_priq_dumb_add #define _priq_wait_add z_priq_dumb_add
#define _priq_wait_remove z_priq_dumb_remove #define _priq_wait_remove z_priq_dumb_remove
#define _priq_wait_best z_priq_dumb_best #define _priq_wait_best z_priq_dumb_best
#endif #endif
/* Dumb Scheduling*/ static ALWAYS_INLINE void z_priq_dumb_remove(sys_dlist_t *pq, struct k_thread *thread)
struct k_thread *z_priq_dumb_best(sys_dlist_t *pq); {
void z_priq_dumb_remove(sys_dlist_t *pq, struct k_thread *thread); ARG_UNUSED(pq);
/* Scalable Scheduling */ sys_dlist_remove(&thread->base.qnode_dlist);
void z_priq_rb_add(struct _priq_rb *pq, struct k_thread *thread); }
void z_priq_rb_remove(struct _priq_rb *pq, struct k_thread *thread);
/* Multi Queue Scheduling */ static ALWAYS_INLINE struct k_thread *z_priq_dumb_best(sys_dlist_t *pq)
struct k_thread *z_priq_mq_best(struct _priq_mq *pq); {
struct k_thread *z_priq_rb_best(struct _priq_rb *pq); struct k_thread *thread = NULL;
sys_dnode_t *n = sys_dlist_peek_head(pq);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_dlist);
}
return thread;
}
bool z_priq_rb_lessthan(struct rbnode *a, struct rbnode *b); static ALWAYS_INLINE void z_priq_rb_add(struct _priq_rb *pq, struct k_thread *thread)
{
struct k_thread *t;
thread->base.order_key = pq->next_order_key++;
/* Renumber at wraparound. This is tiny code, and in practice
* will almost never be hit on real systems. BUT on very
* long-running systems where a priq never completely empties
* AND that contains very large numbers of threads, it can be
* a latency glitch to loop over all the threads like this.
*/
if (!pq->next_order_key) {
RB_FOR_EACH_CONTAINER(&pq->tree, t, base.qnode_rb) {
t->base.order_key = pq->next_order_key++;
}
}
rb_insert(&pq->tree, &thread->base.qnode_rb);
}
static ALWAYS_INLINE void z_priq_rb_remove(struct _priq_rb *pq, struct k_thread *thread)
{
rb_remove(&pq->tree, &thread->base.qnode_rb);
if (!pq->tree.root) {
pq->next_order_key = 0;
}
}
static ALWAYS_INLINE struct k_thread *z_priq_rb_best(struct _priq_rb *pq)
{
struct k_thread *thread = NULL;
struct rbnode *n = rb_get_min(&pq->tree);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_rb);
}
return thread;
}
static ALWAYS_INLINE struct k_thread *z_priq_mq_best(struct _priq_mq *pq)
{
struct k_thread *thread = NULL;
for (int i = 0; i < PRIQ_BITMAP_SIZE; ++i) {
if (!pq->bitmask[i]) {
continue;
}
#ifdef CONFIG_64BIT
sys_dlist_t *l = &pq->queues[i * 64 + u64_count_trailing_zeros(pq->bitmask[i])];
#else
sys_dlist_t *l = &pq->queues[i * 32 + u32_count_trailing_zeros(pq->bitmask[i])];
#endif
sys_dnode_t *n = sys_dlist_peek_head(l);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_dlist);
break;
}
}
return thread;
}
#ifdef CONFIG_SCHED_MULTIQ #ifdef CONFIG_SCHED_MULTIQ
@ -105,4 +181,43 @@ static ALWAYS_INLINE void z_priq_mq_remove(struct _priq_mq *pq,
} }
} }
#endif /* CONFIG_SCHED_MULTIQ */ #endif /* CONFIG_SCHED_MULTIQ */
#ifdef CONFIG_SCHED_CPU_MASK
static ALWAYS_INLINE struct k_thread *z_priq_dumb_mask_best(sys_dlist_t *pq)
{
/* With masks enabled we need to be prepared to walk the list
* looking for one we can run
*/
struct k_thread *thread;
SYS_DLIST_FOR_EACH_CONTAINER(pq, thread, base.qnode_dlist) {
if ((thread->base.cpu_mask & BIT(_current_cpu->id)) != 0) {
return thread;
}
}
return NULL;
}
#endif /* CONFIG_SCHED_CPU_MASK */
#if defined(CONFIG_SCHED_DUMB) || defined(CONFIG_WAITQ_DUMB)
static ALWAYS_INLINE void z_priq_dumb_add(sys_dlist_t *pq,
struct k_thread *thread)
{
struct k_thread *t;
SYS_DLIST_FOR_EACH_CONTAINER(pq, t, base.qnode_dlist) {
if (z_sched_prio_cmp(thread, t) > 0) {
sys_dlist_insert(&t->base.qnode_dlist,
&thread->base.qnode_dlist);
return;
}
}
sys_dlist_append(pq, &thread->base.qnode_dlist);
}
#endif /* CONFIG_SCHED_DUMB || CONFIG_WAITQ_DUMB */
#endif /* ZEPHYR_KERNEL_INCLUDE_PRIORITY_Q_H_ */ #endif /* ZEPHYR_KERNEL_INCLUDE_PRIORITY_Q_H_ */

91
kernel/priority_queues.c
View file

@ -7,26 +7,7 @@
#include <zephyr/kernel.h> #include <zephyr/kernel.h>
#include <ksched.h> #include <ksched.h>
#include <zephyr/sys/math_extras.h> #include <zephyr/sys/math_extras.h>
#include <zephyr/sys/dlist.h>
void z_priq_dumb_remove(sys_dlist_t *pq, struct k_thread *thread)
{
ARG_UNUSED(pq);
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
sys_dlist_remove(&thread->base.qnode_dlist);
}
struct k_thread *z_priq_dumb_best(sys_dlist_t *pq)
{
struct k_thread *thread = NULL;
sys_dnode_t *n = sys_dlist_peek_head(pq);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_dlist);
}
return thread;
}
bool z_priq_rb_lessthan(struct rbnode *a, struct rbnode *b) bool z_priq_rb_lessthan(struct rbnode *a, struct rbnode *b)
{ {
@ -47,73 +28,3 @@ bool z_priq_rb_lessthan(struct rbnode *a, struct rbnode *b)
? 1 : 0; ? 1 : 0;
} }
} }
void z_priq_rb_add(struct _priq_rb *pq, struct k_thread *thread)
{
struct k_thread *t;
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
thread->base.order_key = pq->next_order_key++;
/* Renumber at wraparound. This is tiny code, and in practice
* will almost never be hit on real systems. BUT on very
* long-running systems where a priq never completely empties
* AND that contains very large numbers of threads, it can be
* a latency glitch to loop over all the threads like this.
*/
if (!pq->next_order_key) {
RB_FOR_EACH_CONTAINER(&pq->tree, t, base.qnode_rb) {
t->base.order_key = pq->next_order_key++;
}
}
rb_insert(&pq->tree, &thread->base.qnode_rb);
}
void z_priq_rb_remove(struct _priq_rb *pq, struct k_thread *thread)
{
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
rb_remove(&pq->tree, &thread->base.qnode_rb);
if (!pq->tree.root) {
pq->next_order_key = 0;
}
}
struct k_thread *z_priq_rb_best(struct _priq_rb *pq)
{
struct k_thread *thread = NULL;
struct rbnode *n = rb_get_min(&pq->tree);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_rb);
}
return thread;
}
struct k_thread *z_priq_mq_best(struct _priq_mq *pq)
{
struct k_thread *thread = NULL;
for (int i = 0; i < PRIQ_BITMAP_SIZE; ++i) {
if (!pq->bitmask[i]) {
continue;
}
#ifdef CONFIG_64BIT
sys_dlist_t *l = &pq->queues[i * 64 + u64_count_trailing_zeros(pq->bitmask[i])];
#else
sys_dlist_t *l = &pq->queues[i * 32 + u32_count_trailing_zeros(pq->bitmask[i])];
#endif
sys_dnode_t *n = sys_dlist_peek_head(l);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_dlist);
break;
}
}
return thread;
}

43
kernel/sched.c
View file

@ -82,43 +82,6 @@ int32_t z_sched_prio_cmp(struct k_thread *thread_1,
return 0; return 0;
} }
#ifdef CONFIG_SCHED_CPU_MASK
static ALWAYS_INLINE struct k_thread *_priq_dumb_mask_best(sys_dlist_t *pq)
{
/* With masks enabled we need to be prepared to walk the list
* looking for one we can run
*/
struct k_thread *thread;
SYS_DLIST_FOR_EACH_CONTAINER(pq, thread, base.qnode_dlist) {
if ((thread->base.cpu_mask & BIT(_current_cpu->id)) != 0) {
return thread;
}
}
return NULL;
}
#endif /* CONFIG_SCHED_CPU_MASK */
#if defined(CONFIG_SCHED_DUMB) || defined(CONFIG_WAITQ_DUMB)
static ALWAYS_INLINE void z_priq_dumb_add(sys_dlist_t *pq,
struct k_thread *thread)
{
struct k_thread *t;
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
SYS_DLIST_FOR_EACH_CONTAINER(pq, t, base.qnode_dlist) {
if (z_sched_prio_cmp(thread, t) > 0) {
sys_dlist_insert(&t->base.qnode_dlist,
&thread->base.qnode_dlist);
return;
}
}
sys_dlist_append(pq, &thread->base.qnode_dlist);
}
#endif /* CONFIG_SCHED_DUMB || CONFIG_WAITQ_DUMB */
static ALWAYS_INLINE void *thread_runq(struct k_thread *thread) static ALWAYS_INLINE void *thread_runq(struct k_thread *thread)
{ {
#ifdef CONFIG_SCHED_CPU_MASK_PIN_ONLY #ifdef CONFIG_SCHED_CPU_MASK_PIN_ONLY
@ -150,11 +113,15 @@ static ALWAYS_INLINE void *curr_cpu_runq(void)
static ALWAYS_INLINE void runq_add(struct k_thread *thread) static ALWAYS_INLINE void runq_add(struct k_thread *thread)
{ {
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
_priq_run_add(thread_runq(thread), thread); _priq_run_add(thread_runq(thread), thread);
} }
static ALWAYS_INLINE void runq_remove(struct k_thread *thread) static ALWAYS_INLINE void runq_remove(struct k_thread *thread)
{ {
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
_priq_run_remove(thread_runq(thread), thread); _priq_run_remove(thread_runq(thread), thread);
} }
@ -616,7 +583,7 @@ static void add_to_waitq_locked(struct k_thread *thread, _wait_q_t *wait_q)
if (wait_q != NULL) { if (wait_q != NULL) {
thread->base.pended_on = wait_q; thread->base.pended_on = wait_q;
z_priq_wait_add(&wait_q->waitq, thread); _priq_wait_add(&wait_q->waitq, thread);
} }
} }