On 09/01/2016 03:30 AM, Chunyan Zhang wrote: > From: Ke Wang <ke.wang@xxxxxxxxxxxxxx> > > sunrpc uses workqueue to clean cache regulary. There is no real dependency > of executing work on the cpu which queueing it. > > On a idle system, especially for a heterogeneous systems like big.LITTLE, > it is observed that the big idle cpu was woke up many times just to service > this work, which against the principle of power saving. It would be better > if we can schedule it on a cpu which the scheduler believes to be the most > appropriate one. > > After apply this patch, system_wq will be replaced by > system_power_efficient_wq for sunrpc. This functionality is enabled when > CONFIG_WQ_POWER_EFFICIENT is selected. Makes sense to me, but I'm a little surprised that there isn't a "schedule_delayed_power_efficient_work()" function to match how the normal workqueue is used. Thanks, Anna > > Signed-off-by: Ke Wang <ke.wang@xxxxxxxxxxxxxx> > --- > net/sunrpc/cache.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c > index 4d8e11f..8aabe12 100644 > --- a/net/sunrpc/cache.c > +++ b/net/sunrpc/cache.c > @@ -353,7 +353,7 @@ void sunrpc_init_cache_detail(struct cache_detail *cd) > spin_unlock(&cache_list_lock); > > /* start the cleaning process */ > - schedule_delayed_work(&cache_cleaner, 0); > + queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0); > } > EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail); > > @@ -476,7 +476,8 @@ static void do_cache_clean(struct work_struct *work) > delay = 0; > > if (delay) > - schedule_delayed_work(&cache_cleaner, delay); > + queue_delayed_work(system_power_efficient_wq, > + &cache_cleaner, delay); > } > > > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
