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Mon, 25 Nov 2024 10:01:06 GMT Received: from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A8EDF58062; Mon, 25 Nov 2024 10:01:05 +0000 (GMT) Received: from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3D28E58051; Mon, 25 Nov 2024 10:00:59 +0000 (GMT) Received: from [9.43.78.113] (unknown [9.43.78.113]) by smtpav02.dal12v.mail.ibm.com (Postfix) with ESMTP; Mon, 25 Nov 2024 10:00:58 +0000 (GMT) Message-ID: <244e174a-5449-4730-963e-424a5b3edc05@linux.ibm.com> Date: Mon, 25 Nov 2024 15:30:56 +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 From: Madadi Vineeth Reddy Subject: Re: [PATCH 2/2] sched/fair: Update comments regarding last and skip buddy Reply-To: 20241125021222.356881-3-adamli@os.amperecomputing.com To: Adam Li , peterz@infradead.org, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org Cc: dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org, patches@amperecomputing.com, cl@linux.com, Madadi Vineeth Reddy References: <20241125021222.356881-1-adamli@os.amperecomputing.com> <20241125021222.356881-3-adamli@os.amperecomputing.com> Content-Language: en-US In-Reply-To: <20241125021222.356881-3-adamli@os.amperecomputing.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: I3TFc39esPwcgfUuut8ghgHci1pMq67u X-Proofpoint-GUID: PgviCzTQCtxVNw3ySoRWwVsKUHkPTvhm X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 malwarescore=0 mlxlogscore=960 spamscore=0 suspectscore=0 phishscore=0 clxscore=1011 mlxscore=0 lowpriorityscore=0 impostorscore=0 adultscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2411250085 Hi Adam Li, On 25/11/24 07:42, Adam Li wrote: > Commit 5e963f2bd465 ("sched/fair: Commit to EEVDF") removed the "last" and > "skip" buddy. Update comments in pick_next_entity(). > > Signed-off-by: Adam Li > --- > kernel/sched/fair.c | 8 +------- > 1 file changed, 1 insertion(+), 7 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index cd1188b7f3df..d8826a8e0c77 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5602,17 +5602,11 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) > > 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) > { > /* > + * Pick the "next" buddy, since someone really wants that to run. > * Enabling NEXT_BUDDY will affect latency but not fairness. > */ Yes, the LAST_BUDDY and SKIP_BUDDY are obsolete now. Reviewed-by: Madadi Vineeth Reddy Thanks, Madadi Vineeth Reddy > if (sched_feat(NEXT_BUDDY) &&