From f2c96ac4dedf4976e46de34c69c2cd8b289c4ef2 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 2 Feb 2016 14:03:06 +0100 Subject: [PATCH] credit: update timeslice under lock When updating the timeslice of the credit scheduler protect the scheduler's private data by it's lock. Today a possible race could result only in some weird scheduling decisions during one timeslice, but further adjustments will need the lock anyway. Signed-off-by: Juergen Gross Reviewed-by: Dario Faggioli --- xen/common/sched_credit.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/xen/common/sched_credit.c b/xen/common/sched_credit.c index 03fb2c2d67..8fbbd54637 100644 --- a/xen/common/sched_credit.c +++ b/xen/common/sched_credit.c @@ -1101,6 +1101,7 @@ csched_sys_cntl(const struct scheduler *ops, int rc = -EINVAL; xen_sysctl_credit_schedule_t *params = &sc->u.sched_credit; struct csched_private *prv = CSCHED_PRIV(ops); + unsigned long flags; switch ( sc->cmd ) { @@ -1112,8 +1113,12 @@ csched_sys_cntl(const struct scheduler *ops, || params->ratelimit_us < XEN_SYSCTL_SCHED_RATELIMIT_MIN)) || MICROSECS(params->ratelimit_us) > MILLISECS(params->tslice_ms) ) goto out; + + spin_lock_irqsave(&prv->lock, flags); __csched_set_tslice(prv, params->tslice_ms); prv->ratelimit_us = params->ratelimit_us; + spin_unlock_irqrestore(&prv->lock, flags); + /* FALLTHRU */ case XEN_SYSCTL_SCHEDOP_getinfo: params->tslice_ms = prv->tslice_ms; -- 2.39.5