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samples/synchronization: Clean up SMP CPU pinning example

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There was some code to demonstrate the cpu_mask API here, but it was
asymmetric (only thread B was pinned) and assumed exactly two CPUs.

Start both threads pinned to CPUs 0 and 1 from an external main, and
predicate the pinning on there actually being more than one SMP CPU.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This commit is contained in:
Andy Ross 2021-02-12 13:04:32 -08:00 committed by Anas Nashif
parent c348a05d5a
commit 686b9fff5e
2 changed files with 32 additions and 14 deletions
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1
samples/synchronization/prj.conf
View file

@ -1,3 +1,4 @@
CONFIG_STDOUT_CONSOLE=y
# enable to use thread names
CONFIG_THREAD_NAME=y
CONFIG_SCHED_CPU_MASK=y

45
samples/synchronization/src/main.c
View file

@ -16,6 +16,9 @@
* world application would likely use the static approach for both threads.
*/
#define PIN_THREADS (IS_ENABLED(CONFIG_SMP) \
&& IS_ENABLED(CONFIG_SCHED_CPU_MASK) \
&& (CONFIG_MP_NUM_CPUS > 1))
/* size of stack area used by each thread */
#define STACKSIZE 1024
@ -84,6 +87,9 @@ void threadB(void *dummy1, void *dummy2, void *dummy3)
helloLoop(__func__, &threadB_sem, &threadA_sem);
}
K_THREAD_STACK_DEFINE(threadA_stack_area, STACKSIZE);
static struct k_thread threadA_data;
K_THREAD_STACK_DEFINE(threadB_stack_area, STACKSIZE);
static struct k_thread threadB_data;
@ -95,21 +101,32 @@ void threadA(void *dummy1, void *dummy2, void *dummy3)
ARG_UNUSED(dummy2);
ARG_UNUSED(dummy3);
/* spawn threadB */
k_tid_t tid = k_thread_create(&threadB_data, threadB_stack_area,
STACKSIZE, threadB, NULL, NULL, NULL,
PRIORITY, 0, K_FOREVER);
k_thread_name_set(tid, "thread_b");
#if CONFIG_SCHED_CPU_MASK
k_thread_cpu_mask_disable(&threadB_data, 1);
k_thread_cpu_mask_enable(&threadB_data, 0);
#endif
k_thread_start(&threadB_data);
/* invoke routine to ping-pong hello messages with threadB */
helloLoop(__func__, &threadA_sem, &threadB_sem);
}
K_THREAD_DEFINE(thread_a, STACKSIZE, threadA, NULL, NULL, NULL,
PRIORITY, 0, 0);
void main(void)
{
k_thread_create(&threadA_data, threadA_stack_area,
K_THREAD_STACK_SIZEOF(threadA_stack_area),
threadA, NULL, NULL, NULL,
PRIORITY, 0, K_FOREVER);
k_thread_name_set(&threadA_data, "thread_a");
#if PIN_THREADS
k_thread_cpu_mask_clear(&threadA_data);
k_thread_cpu_mask_enable(&threadA_data, 0);
#endif
k_thread_create(&threadB_data, threadB_stack_area,
K_THREAD_STACK_SIZEOF(threadB_stack_area),
threadB, NULL, NULL, NULL,
PRIORITY, 0, K_FOREVER);
k_thread_name_set(&threadB_data, "thread_b");
#if PIN_THREADS
k_thread_cpu_mask_clear(&threadB_data);
k_thread_cpu_mask_enable(&threadB_data, 1);
#endif
k_thread_start(&threadA_data);
k_thread_start(&threadB_data);
}