Re: [PATCH v01] sched/core: uclamp: fix rq.uclamp memory size of initialization

From: Peter Zijlstra
Date: Tue Jan 07 2020 - 04:48:33 EST


On Sun, Dec 29, 2019 at 10:11:20PM +0000, Qais Yousef wrote:
> On 12/25/19 15:44, Li Guanglei wrote:
> > From: Li Guanglei <guanglei.li@xxxxxxxxxx>
> >
> > uclamp_rq for each clamp id(UCLAMP_CNT) should be initialized when call
>
> s/clamp id(UCLAMP_CNT)/UCLAMP_CNT/
>
> > init_uclamp.
> >
> > Signed-off-by: Li Guanglei <guanglei.li@xxxxxxxxxx>
>
> This need fixes tag
>
> Fixes: 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcountinga")
>
> Otherwise this looks good to me.
>
> Reviewed-by: Qais Yousef <qais.yousef@xxxxxxx>

Thanks! It now looks something like so:

---
Subject: sched/core: Fix size of rq::uclamp initialization
From: Li Guanglei <guanglei.li@xxxxxxxxxx>
Date: Wed, 25 Dec 2019 15:44:04 +0800

rq::uclamp is an array of struct uclamp_rq, make sure we clear the
whole thing.

Fixes: 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcountinga")
Signed-off-by: Li Guanglei <guanglei.li@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Qais Yousef <qais.yousef@xxxxxxx>
Link: https://lkml.kernel.org/r/1577259844-12677-1-git-send-email-guangleix.li@xxxxxxxxx
---
kernel/sched/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1253,7 +1253,8 @@ static void __init init_uclamp(void)
mutex_init(&uclamp_mutex);

for_each_possible_cpu(cpu) {
- memset(&cpu_rq(cpu)->uclamp, 0, sizeof(struct uclamp_rq));
+ memset(&cpu_rq(cpu)->uclamp, 0,
+ sizeof(struct uclamp_rq)*UCLAMP_CNT);
cpu_rq(cpu)->uclamp_flags = 0;
}