Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220712150506.632304-1-schspa@gmail.com> <20220712150506.632304-2-schspa@gmail.com>
 <5f0d6bef-9e9e-7083-9657-ae5e6dd10d2a@arm.com>
In-Reply-To: <5f0d6bef-9e9e-7083-9657-ae5e6dd10d2a@arm.com>
From:   Schspa Shi <schspa@gmail.com>
Date:   Wed, 13 Jul 2022 20:24:27 +0800
Message-ID: <CAMA88Tre3iVu+Dsxv4W_eWY2TrTPR-j_hfXVzQPCEynnCbgBeg@mail.gmail.com>
Subject: Re: [PATCH v6 2/2] sched/rt: Trying to push current task when target
 disable migrating
To:     Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc:     mingo@redhat.com, Peter Zijlstra <peterz@infradead.org>,
        juri.lelli@redhat.com, vincent.guittot@linaro.org,
        Steven Rostedt <rostedt@goodmis.org>,
        Benjamin Segall <bsegall@google.com>, mgorman@suse.de,
        bristot@redhat.com, Valentin Schneider <vschneid@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Dietmar Eggemann <dietmar.eggemann@arm.com> writes:

> On 12/07/2022 17:05, Schspa Shi wrote:
>
> [...]
>
>> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
>> index 7bd3e6ecbe45e..e2d7b085a93d9 100644
>> --- a/kernel/sched/rt.c
>> +++ b/kernel/sched/rt.c
>> @@ -2136,6 +2136,12 @@ static int push_rt_task(struct rq *rq, bool pull)
>>               */
>>              task = pick_next_pushable_task(rq);
>>              if (task == next_task) {
>> +                    /*
>> +                     * If next task has now disabled migrating, see if we
>> +                     * can push the current task.
>> +                     */
>> +                    if (unlikely(is_migration_disabled(task)))
>
> Doesn't this need a `put_task_struct(next_task)`?

Thanks for the review, I missed this.

>
>> +                            goto retry;
>>                      /*
>>                       * The task hasn't migrated, and is still the next
>>                       * eligible task, but we failed to find a run-queue
>
> Why not introduce in push_dl_task() as well?

OK, push_dl_task() needs this too, I missed it.

I will upload a new patch version to fix it.


-- 
BRs
Schspa Shi