Re: çå: [PATCH] sunrpc: queue work on system_power_efficient_wq
From: Anna Schumaker
Date: Mon Sep 26 2016 - 16:56:38 EST
I took a second look at the patch and it still looks okay to me. It's in my git tree for 4.9.
On 09/19/2016 10:33 PM, Ke Wang (çç) wrote:
> May I have any comments for this patch?
> This patch can be merged directly into next release?
> åää: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
> åéæé: 2016å9æ2æ 2:46
> æää: Chunyan Zhang; trond.myklebust@xxxxxxxxxxxxxxx; anna.schumaker@xxxxxxxxxx; davem@xxxxxxxxxxxxx
> æé: linux-nfs@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Ke Wang (çç)
> äé: Re: [PATCH] sunrpc: queue work on system_power_efficient_wq
> 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.
>> 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)
>> /* start the cleaning process */
>> - schedule_delayed_work(&cache_cleaner, 0);
>> + queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0);
>> @@ -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);