From: George Dunlap Date: Fri, 18 May 2018 10:12:25 +0000 (+0200) Subject: xen: Introduce vcpu_sleep_nosync_locked() X-Git-Tag: archive/raspbian/4.8.3+xsa262+shim4.10.0+comet3-1+deb9u7+rpi1^2~16 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=e2c4d0bd625ac6e227b2823253ff9fbc8ce1c445;p=xen.git xen: Introduce vcpu_sleep_nosync_locked() There are a lot of places which release a lock before calling vcpu_sleep_nosync(), which then just grabs the lock again. This is not only a waste of time, but leads to more code duplication (since you have to copy-and-paste recipes rather than calling a unified function), which in turn leads to an increased chance of bugs. Introduce vcpu_sleep_nosync_locked(), which can be called if you already hold the schedule lock. Signed-off-by: George Dunlap Reviewed-by: Dario Faggioli master commit: da0a5e00de8aa93f2a7482d138dbee9dec2aa5c2 master date: 2018-05-03 11:56:36 +0100 (cherry picked from commit d66898a15d47779a608f30413cdf629389f5037a) Gbp-Pq: Name xen-introduce-vcpu_sleep_nosync_locked.patch --- diff --git a/xen/common/schedule.c b/xen/common/schedule.c index b1e3225208..47ae49efd4 100644 --- a/xen/common/schedule.c +++ b/xen/common/schedule.c @@ -424,14 +424,9 @@ void sched_destroy_domain(struct domain *d) cpupool_rm_domain(d); } -void vcpu_sleep_nosync(struct vcpu *v) +void vcpu_sleep_nosync_locked(struct vcpu *v) { - unsigned long flags; - spinlock_t *lock; - - TRACE_2D(TRC_SCHED_SLEEP, v->domain->domain_id, v->vcpu_id); - - lock = vcpu_schedule_lock_irqsave(v, &flags); + ASSERT(spin_is_locked(per_cpu(schedule_data,v->processor).schedule_lock)); if ( likely(!vcpu_runnable(v)) ) { @@ -440,6 +435,18 @@ void vcpu_sleep_nosync(struct vcpu *v) SCHED_OP(VCPU2OP(v), sleep, v); } +} + +void vcpu_sleep_nosync(struct vcpu *v) +{ + unsigned long flags; + spinlock_t *lock; + + TRACE_2D(TRC_SCHED_SLEEP, v->domain->domain_id, v->vcpu_id); + + lock = vcpu_schedule_lock_irqsave(v, &flags); + + vcpu_sleep_nosync_locked(v); vcpu_schedule_unlock_irqrestore(lock, flags, v); }