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Sun, 13 Apr 2025 04:10:50 GMT Received: from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2F5BA5804B; Sun, 13 Apr 2025 04:10:50 +0000 (GMT) Received: from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6613A58055; Sun, 13 Apr 2025 04:10:46 +0000 (GMT) Received: from [9.43.111.221] (unknown [9.43.111.221]) by smtpav01.wdc07v.mail.ibm.com (Postfix) with ESMTP; Sun, 13 Apr 2025 04:10:46 +0000 (GMT) Message-ID: <4da6d43b-59f6-48e4-b58c-2f0792035851@linux.ibm.com> Date: Sun, 13 Apr 2025 09:40:44 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] sched/fair: Remove stale references to LAST_BUDDY and SKIP_BUDDY To: Peter Zijlstra , Ingo Molnar Cc: Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , LKML , Adam Li , Madadi Vineeth Reddy References: <20250314090128.25141-1-vineethr@linux.ibm.com> Content-Language: en-US Reply-To: 20250314090128.25141-1-vineethr@linux.ibm.com From: Madadi Vineeth Reddy In-Reply-To: <20250314090128.25141-1-vineethr@linux.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: wmwTjYeqZfRS9iC4-6RUXg9LTTkaMkdS X-Proofpoint-GUID: ksDGHrEE1nTBlhH7Y4-Y47NUkwX0fPuy X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1095,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-04-13_02,2025-04-10_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 adultscore=0 mlxlogscore=758 impostorscore=0 lowpriorityscore=0 malwarescore=0 priorityscore=1501 bulkscore=0 phishscore=0 clxscore=1015 spamscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2502280000 definitions=main-2504130028 Hi Peter, Ingo, Ping. Any thoughts on this? Can it be picked up? Thanks, Madadi Vineeth Reddy On 14/03/25 14:31, Madadi Vineeth Reddy wrote: > Commit 5e963f2bd465 ("sched/fair: Commit to EEVDF") removed the > functionality associated with LAST_BUDDY and SKIP_BUDDY. However, > some outdated references remained in the comments for pick_next_entity > and check_preempt_wakeup_fair. This commit cleans up those comments > to maintain clarity and correctness. > > No functional change intended. > > Co-developed-by: Adam Li > Signed-off-by: Adam Li > Signed-off-by: Madadi Vineeth Reddy > --- > kernel/sched/fair.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 9dafb374d76d..379dbcbb24e9 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5578,8 +5578,6 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags); > * Pick the next process, keeping these things in mind, in this order: > * 1) keep things fair between processes/task groups > * 2) pick the "next" process, since someone really wants that to run > - * 3) pick the "last" process, for cache locality > - * 4) do not run the "skip" process, if something else is available > */ > static struct sched_entity * > pick_next_entity(struct rq *rq, struct cfs_rq *cfs_rq) > @@ -8780,9 +8778,7 @@ static void check_preempt_wakeup_fair(struct rq *rq, struct task_struct *p, int > * > * Note: this also catches the edge-case of curr being in a throttled > * group (e.g. via set_curr_task), since update_curr() (in the > - * enqueue of curr) will have resulted in resched being set. This > - * prevents us from potentially nominating it as a false LAST_BUDDY > - * below. > + * enqueue of curr) will have resulted in resched being set. > */ > if (test_tsk_need_resched(rq->curr)) > return;