diff options
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_sched.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/sys/kern/kern_sched.c b/sys/kern/kern_sched.c index e259a2c..23a1ebb 100644 --- a/sys/kern/kern_sched.c +++ b/sys/kern/kern_sched.c @@ -78,13 +78,37 @@ sched_oneshot(bool now) timer.oneshot_us(usec); } +/* + * Returns true if a processor is associated + * with a specific thread + * + * @ci: CPU that wants to take 'td' + * @td: Thread to check against + */ +static bool +cpu_is_assoc(struct cpu_info *ci, struct proc *td) +{ + /* + * If we are not pinned, any processor is + * associated. + */ + if (!ISSET(td->flags, PROC_PINNED)) { + return true; + } + + return ci->id == td->affinity; +} + struct proc * sched_dequeue_td(void) { struct sched_queue *queue; struct proc *td = NULL; + struct cpu_info *ci; + uint32_t ncpu = 0; spinlock_acquire(&tdq_lock); + ci = this_cpu(); for (size_t i = 0; i < SCHED_NQUEUE; ++i) { queue = &qlist[i]; @@ -104,6 +128,19 @@ sched_dequeue_td(void) } } + /* + * If we are on a multicore system and this isn't + * our process, don't take it. Some threads might + * be pinned to a specific processor. + */ + ncpu = cpu_count(); + while (!cpu_is_assoc(ci, td) && ncpu > 1) { + td = TAILQ_NEXT(td, link); + if (td == NULL) { + break; + } + } + if (td == NULL) { continue; } @@ -249,6 +286,35 @@ sched_detach(struct proc *td) spinlock_release(&tdq_lock); } +/* + * Pin a process to a specific processor + * + * @td: Process to pin + * @cpu: Logical processor ID to pin `td' to. + * + * XXX: 'cpu' is a machine independent value, representing + * CPU<n> + */ +void +proc_pin(struct proc *td, affinity_t cpu) +{ + td->affinity = cpu; + td->flags |= PROC_PINNED; +} + +/* + * Unpin a pinned process, allowing it to be + * picked up by any processor + * + * @td: Process to unpin + */ +void +proc_unpin(struct proc *td) +{ + td->affinity = 0; + td->flags &= ~PROC_PINNED; +} + void sched_init(void) { |