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Wed, 13 May 2026 04:15:54 +0000 (GMT) Received: from [9.39.28.2] (unknown [9.39.28.2]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 13 May 2026 04:15:54 +0000 (GMT) Message-ID: Date: Wed, 13 May 2026 09:45:53 +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 v2 3/3] sched/fair: Add compile time check in fastpaths for CONFIG_SCHED_SMT=n To: Phil Auld Cc: mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, linux-kernel@vger.kernel.org, kprateek.nayak@amd.com, juri.lelli@redhat.com, vschneid@redhat.com, dietmar.eggemann@arm.com, tj@kernel.org, rostedt@goodmis.org, mgorman@suse.de, bsegall@google.com, arighi@nvidia.com References: <20260512152125.308280-1-sshegde@linux.ibm.com> <20260512152125.308280-4-sshegde@linux.ibm.com> <20260512165927.GD140541@pauld.westford.csb> Content-Language: en-US From: Shrikanth Hegde In-Reply-To: <20260512165927.GD140541@pauld.westford.csb> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-ORIG-GUID: NE90bzuDAOIewn_g4wEjqGVs8n7zpt8d X-Proofpoint-GUID: aZ8wPEA7XwaLEvDeR2gWCs3mxjgWBVhf X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNTEzMDAzNyBTYWx0ZWRfX/puwGUBmLpYi j8fDIsv6pgp6Zr/ucrTHaHymLr+Cb5AjrVc09W0+LXrspQmRTFGUWOM6Bjp5q+KhTCvHNEMCj2v sgvfFPTzsICsg7RTUhIxGgslkqQ9ys1lBdjqT9l1+B4QdoV9B88opP+Iz0p5vCzHmr50Z/739aY MHy/cY3EU40vx24kisHFUsKnhUSsXujX1v1oOT6lthVHD/axA/U6zua3evB/RNycO2CxgNJOF8p R3g5JBcy+h9QivvXukIGSV6Z2E6p1hPmzo0FdXnx9lxwp3Sr35wcW2gjVLDE8heTOlNdGQVVksX vdRVcrjwOIFJfG5WzwBn35AcS5Pzr8txG0xFatsbZSW5wawnl1kGCqKInltUY8LZrD8nFtpAYL4 qoPyKBpb9fo9K31kCb5HKOFRpg5zRGYXHM98e/VJjEF1sVKdkIMOeRWCp5f2cFlpHSX0U0kk98Z BPcgn+/jfCMC4nl+u6A== X-Authority-Analysis: v=2.4 cv=P8UKQCAu c=1 sm=1 tr=0 ts=6a03fb00 cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=IkcTkHD0fZMA:10 a=NGcC8JguVDcA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=20KFwNOVAAAA:8 a=4ceElk5AHO0yBz9pvpcA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-05-11_05,2026-05-08_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 priorityscore=1501 phishscore=0 bulkscore=0 clxscore=1011 malwarescore=0 spamscore=0 lowpriorityscore=0 suspectscore=0 impostorscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2605050000 definitions=main-2605130037 Hi Phil. On 5/12/26 10:29 PM, Phil Auld wrote: > Hi Shrikanth, > > On Tue, May 12, 2026 at 08:51:25PM +0530 Shrikanth Hegde wrote: >> For fastpaths such as wakeup, load balance even a minimal code additons >> can pop up. Add IS_ENABLED checks there to ensure there is no overhead. > > "For fastpaths such as wakeup and load balance, even minimal code additions > can add up. Add IS_ENABLED() checks..." ? > Ok. >> >> Other places are either have sched_smt_active() check or they are not in > > s/are// ok. > > "have a sched_smt_active_check()" or drop "check" ? > > I was saying sched_smt_active() runtime gating is there for many fast paths where cpu_smt_mask is being referred or those code paths are not fast paths. Let me re-word a bit. > Otherwise lgtm. > > Reviewed-by: Phil Auld > > > Cheers, > Phil > Thanks for the review.