TSC's get reset after suspend/resume and this leads to a scenario of rq->clock (sched_clock_cpu()) less than rq->age_stamp. This leads to a big value returned by scale_rt_power() and the resulting big group power set by the update_group_power() is causing improper load balancing between busy and idle cpu's after suspend/resume. This resulted in multi-threaded workloads (like kernel-compilation) go slower after suspend/resume cycle on core i5 laptops. Realign rq->age_stamp to rq->clock and reset rq->rt_avg in rq_online_rt(). Addresses the primary issue reported in the https://bugzilla.kernel.org/show_bug.cgi?id=15559 (Bad performance after suspend on Intel i7 and i5) Reported-by: Florian Pritz Signed-off-by: Suresh Siddha Cc: stable@kernel.org [2.6.32+] --- diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index d10c80e..a00af73 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -1550,6 +1550,12 @@ static void rq_online_rt(struct rq *rq) __enable_runtime(rq); cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); + + /* + * Reset RT average stat and its time stamp. + */ + rq->age_stamp = rq->clock; + rq->rt_avg = 0; } /* Assumes rq->lock is held */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/