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Shenoy" , Vincent Guittot , Chen Yu , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Hillf Danton , Shrikanth Hegde , Jianyong Wu , Yangyu Chen , Tingyin Duan , Vern Hao , Vern Hao , Len Brown , Aubrey Li , Zhao Liu , Chen Yu , Adam Li , Aaron Lu , Tim Chen , Josh Don , Gavin Guo , Qais Yousef , Libo Chen , linux-kernel@vger.kernel.org, Madadi Vineeth Reddy References: <20260219165507.GN1395266@noisy.programming.kicks-ass.net> Content-Language: en-US From: Madadi Vineeth Reddy In-Reply-To: <20260219165507.GN1395266@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Authority-Analysis: v=2.4 cv=dvvWylg4 c=1 sm=1 tr=0 ts=699801e4 cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=IkcTkHD0fZMA:10 a=HzLeVaNsDn8A:10 a=VkNPw1HP01LnGYTKEx00:22 a=Mpw57Om8IfrbqaoTuvik:22 a=GgsMoib0sEa3-_RKJdDe:22 a=bnEmu5uOcB2lwwpmSeoA:9 a=QEXdDO2ut3YA:10 a=zZCYzV9kfG8A:10 X-Proofpoint-GUID: Gi8RGbox4V8hPvdk4zohTZ1UI7MladDH X-Proofpoint-ORIG-GUID: TNIrdblNmnVC8NK1M3EXy8RLpSRsgpFX X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMjIwMDA1MiBTYWx0ZWRfX820ZJ+TPVzGT cZQ0Q+4xgUgED3lqsNcTpN+t77SzlffxcKl6AWeKE9KQJgnjv1pNinenjIgBw4YU5fAr5sMVYxd olRYIAbviCn7GRD96C8+sfJHwIP0dykxIcSA5FFg2fPB8TJ8BImMCdEv97udd9Poavi9YC1GnpE 2wyg0dQA0A11abFdzWcC8cUt80HED7ub8gkzWo6W/juwDipwkUkwLeiET9OJaAYD3vHeMz4ZI8j oGN9iYbpWJAkCY+dAKF8XhSfDXa1Ca2P1xD88IEw/2R2rRE2jOE89Yfq1J/Z67JuctFRE285hmv nKarhK/091+1kP2Eu3/NvKeVogKKSMs877m2YTQ4Acw8WTOL/r2oSxJAipi/OlNVLrYkIroOsOM 0SU41NI7dip+56c/DQ0TOEx1Duf7b97iD4af92/81JuoiTdnHo5cqDfsEbqXaeGwQVvTNnxmuRC tqLS3RdZCIcq8Ucu/5w== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-02-19_06,2026-02-20_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 lowpriorityscore=0 impostorscore=0 adultscore=0 priorityscore=1501 clxscore=1015 malwarescore=0 phishscore=0 suspectscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2601150000 definitions=main-2602200052 Hi Peter, On 19/02/26 22:25, Peter Zijlstra wrote: > On Wed, Feb 18, 2026 at 11:24:05PM +0530, Madadi Vineeth Reddy wrote: >> Is there a way to make this useful for architectures with small LLC >> sizes? One possible approach we were exploring is to have LLC at a >> hemisphere level that comprise multiple SMT4 cores. > > Is this hemisphere an actual physical cache level, or would that be > artificial? It's artificial. There is no cache being shared at this level but this is still the level where some amount of cache-snooping takes place and it is relatively faster to access the data from the caches of the cores within this domain. We verified with this producer consumer workload where the producer and consumer threads placed in the same hemisphere showed measurably better latency compared to cross-hemisphere placement. Thanks, Vineeth