diff options
| -rw-r--r-- | xen/common/sched_credit.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c index e7a3fef6ea..7ec960501b 100644 --- a/xen/common/sched_credit.c +++ b/xen/common/sched_credit.c @@ -72,6 +72,9 @@ #define CSCHED_VCPU(_vcpu) ((struct csched_vcpu *) (_vcpu)->sched_priv) #define CSCHED_DOM(_dom) ((struct csched_dom *) (_dom)->sched_priv) #define RUNQ(_cpu) (&(CSCHED_PCPU(_cpu)->runq)) +/* Is the first element of _cpu's runq its idle vcpu? */ +#define IS_RUNQ_IDLE(_cpu) (list_empty(RUNQ(_cpu)) || \ + is_idle_vcpu(__runq_elem(RUNQ(_cpu)->next)->vcpu)) #define CSCHED_CPUONLINE(_pool) \ (((_pool) == NULL) ? &cpupool_free_cpus : &(_pool)->cpu_valid) @@ -488,9 +491,14 @@ _csched_cpu_pick(const struct scheduler *ops, struct vcpu *vc, bool_t commit) * distinct cores first and guarantees we don't do something stupid * like run two VCPUs on co-hyperthreads while there are idle cores * or sockets. + * + * Notice that, when computing the "idleness" of cpu, we may want to + * discount vc. That is, iff vc is the currently running and the only + * runnable vcpu on cpu, we add cpu to the idlers. */ cpus_and(idlers, cpu_online_map, CSCHED_PRIV(ops)->idlers); - cpu_set(cpu, idlers); + if ( vc->processor == cpu && IS_RUNQ_IDLE(cpu) ) + cpu_set(cpu, idlers); cpus_and(cpus, cpus, idlers); cpu_clear(cpu, cpus); |