diff options
Diffstat (limited to 'sys/kern/kern_switch.c')
| -rw-r--r-- | sys/kern/kern_switch.c | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/sys/kern/kern_switch.c b/sys/kern/kern_switch.c index 54d0025..e36128f 100644 --- a/sys/kern/kern_switch.c +++ b/sys/kern/kern_switch.c @@ -89,6 +89,7 @@ reassigned to keep this true. __FBSDID("$FreeBSD$"); #include "opt_full_preemption.h" +#include "opt_sched.h" #include <sys/param.h> #include <sys/systm.h> @@ -104,6 +105,10 @@ __FBSDID("$FreeBSD$"); #include <sys/smp.h> #endif #include <machine/critical.h> +#if defined(SMP) && defined(SCHED_4BSD) +#include <sys/sysctl.h> +#endif + CTASSERT((RQB_BPW * RQB_LEN) == RQ_NQS); @@ -686,6 +691,12 @@ runq_check(struct runq *rq) return (0); } +#if defined(SMP) && defined(SCHED_4BSD) +int runq_fuzz = 1; +SYSCTL_DECL(_kern_sched); +SYSCTL_INT(_kern_sched, OID_AUTO, runq_fuzz, CTLFLAG_RW, &runq_fuzz, 0, ""); +#endif + /* * Find the highest priority process on the run queue. */ @@ -699,7 +710,28 @@ runq_choose(struct runq *rq) mtx_assert(&sched_lock, MA_OWNED); while ((pri = runq_findbit(rq)) != -1) { rqh = &rq->rq_queues[pri]; - ke = TAILQ_FIRST(rqh); +#if defined(SMP) && defined(SCHED_4BSD) + /* fuzz == 1 is normal.. 0 or less are ignored */ + if (runq_fuzz > 1) { + /* + * In the first couple of entries, check if + * there is one for our CPU as a preference. + */ + int count = runq_fuzz; + int cpu = PCPU_GET(cpuid); + struct kse *ke2; + ke2 = ke = TAILQ_FIRST(rqh); + + while (count-- && ke2) { + if (ke->ke_thread->td_lastcpu == cpu) { + ke = ke2; + break; + } + ke2 = TAILQ_NEXT(ke2, ke_procq); + } + } else +#endif + ke = TAILQ_FIRST(rqh); KASSERT(ke != NULL, ("runq_choose: no proc on busy queue")); CTR3(KTR_RUNQ, "runq_choose: pri=%d kse=%p rqh=%p", pri, ke, rqh); |
