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: <20221025061846.447975-1-brolerliew@gmail.com>
In-Reply-To: <20221025061846.447975-1-brolerliew@gmail.com>
From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Tue, 25 Oct 2022 09:35:48 -0400
Message-ID: <CADnq5_NweAo-7snRLkidNkOizu7Ft+7GgXCS2Rnv1oxmRFb_RQ@mail.gmail.com>
Subject: Re: [PATCH] drm/scheduler: set current_entity to next when remove
 from rq
To:     brolerliew <brolerliew@gmail.com>,
        "Tuikov, Luben" <Luben.Tuikov@amd.com>
Cc:     Andrey Grodzovsky <andrey.grodzovsky@amd.com>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

+ Luben

On Tue, Oct 25, 2022 at 2:55 AM brolerliew <brolerliew@gmail.com> wrote:
>
> When entity move from one rq to another, current_entity will be set to NULL
> if it is the moving entity. This make entities close to rq head got
> selected more frequently, especially when doing load balance between
> multiple drm_gpu_scheduler.
>
> Make current_entity to next when removing from rq.
>
> Signed-off-by: brolerliew <brolerliew@gmail.com>
> ---
>  drivers/gpu/drm/scheduler/sched_main.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index 2fab218d7082..00b22cc50f08 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -168,10 +168,11 @@ void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
>         spin_lock(&rq->lock);
>
>         atomic_dec(rq->sched->score);
> -       list_del_init(&entity->list);
>
>         if (rq->current_entity == entity)
> -               rq->current_entity = NULL;
> +               rq->current_entity = list_next_entry(entity, list);
> +
> +       list_del_init(&entity->list);
>
>         if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
>                 drm_sched_rq_remove_fifo_locked(entity);
> --
> 2.34.1
>