stv0g/metalsvm
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

minor changes in the scheduler routine to relalize a fair round-robin scheduling

Browse source
This commit is contained in:
Stefan Lankes 2011-08-03 15:10:58 +02:00
parent 577300919c
commit 22dab59699
1 changed files with 14 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
kernel/tasks.c
View file

@ -789,6 +789,15 @@ int block_task(tid_t id)
return ret;
}
/*
* we use this struct to guarantee that the id
* has its own cache line
*/
typedef struct {
uint32_t id __attribute__ ((aligned (CACHE_LINE)));
uint8_t gap[CACHE_LINE-sizeof(uint32_t)];
} last_id_t;
/** @brief _The_ scheduler procedure
*
* Manages scheduling - right now this is just a round robin scheduler.
@ -797,8 +806,9 @@ void scheduler(void)
{
task_t* orig_task;
task_t* curr_task;
unsigned int i;
unsigned int new_id;
uint32_t i;
uint32_t new_id;
static last_id_t last_id = { 0 };
#if MAX_CORES > 1
spinlock_irqsave_lock(&table_lock);
@ -816,7 +826,7 @@ void scheduler(void)
curr_task->flags &= ~TASK_FPU_USED;
}
for(i=1, new_id=(curr_task->id + 1) % MAX_TASKS;
for(i=1, new_id=(last_id.id + 1) % MAX_TASKS;
i<MAX_TASKS; i++, new_id=(new_id+1) % MAX_TASKS)
{
if (task_table[new_id].status == TASK_READY) {
@ -824,6 +834,7 @@ void scheduler(void)
curr_task->status = TASK_READY;
task_table[new_id].status = TASK_RUNNING;
curr_task = per_core(current_task) = task_table+new_id;
last_id.id = new_id;
goto get_task_out;
}