From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-op-o12.zoho.com (sender4-op-o12.zoho.com [136.143.188.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86F382E36F6 for ; Sun, 6 Jul 2025 03:06:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.12 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751771212; cv=pass; b=BiPtnMPBzPKvds3EUXc9qNBxfrt1Zg87kaNf72500d68ywGXKrjTnCh2CFdTanEP7I/RIktBp/iPAy/IqYEyu0HrrqDOrMoUPVFQKirM9rv+IoZu2jwoVVAtW3YGynBz2K2Qi8POp0fLCFweQsxx84i0ew94a7DwVyLkn7V2vV8= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751771212; c=relaxed/simple; bh=ddlUgXhqoj41WdlFKrngejGXPJ1fpcjnBG8qek09PnE=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; b=sXI/Q3tdWDCf3tBMUYvqH5mXGKAYW8T5442c+VskEYAmvqy7OBtCy8IVS9XOcrAti59bZWK8pVgYAqZuK15KWus7iZAknO+Z8POr5tp554Fi+TSo+Xc2wmssgvlAHTW4yQBdGwePz2zBCb8OKznYG8oDG6KiZjFxdmiGA5etfrI= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux.beauty; spf=pass smtp.mailfrom=linux.beauty; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b=PY5bfbpw; arc=pass smtp.client-ip=136.143.188.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux.beauty Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.beauty Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b="PY5bfbpw" ARC-Seal: i=1; a=rsa-sha256; t=1751771205; cv=none; d=zohomail.com; s=zohoarc; b=JrvI4JRu3lNCucShp6eZ5YwmVFlEak0Ftz0gPdUZaf2an5apgnOTjBGCDW0n4qPCz83ijHzZMQBmlhCOEMh5XRuEGHu2KAq40aP42dAI21KMA5WpalmswXARUlTB5evrBsSChUh6/PMMuFoGhBVYHaEflEVCqWl3kxeB6IyJXCo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1751771205; h=Content-Type:Content-Transfer-Encoding:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To:Cc; bh=7kjdld81wUq7y8PDAZ+vU+RLxvhuoDRPjvJUCsxFJjA=; b=gFkVF8DyCn6157Fqh1yxO/jpvA2JjXSRUpP2djkf3gFGNn0ti9ftW292sihFfS38RNv9IK76T2npPfo/hDKz/KsVP2wqzu9G0M+m+He4TAcyohULTtAm/yxX6BRwNexh4uhy+VH45Zk5UXsFTfNqAsFGMBIYsWZIG4RoEwn1ljk= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=linux.beauty; spf=pass smtp.mailfrom=me@linux.beauty; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1751771204; s=zmail; d=linux.beauty; i=me@linux.beauty; h=From:From:To:To:Subject:Subject:Date:Date:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To:Cc; bh=7kjdld81wUq7y8PDAZ+vU+RLxvhuoDRPjvJUCsxFJjA=; b=PY5bfbpw6IB79dxIXDnXrxDzOWdjEdnWfyLLZavpmcVldW1KHXGFmG4ulumR6UHK 6vjoVfPGIkqj/qAtjwBNgcDI9AZUOx96TfWUSTUmN6IOi18oiQNcRcs/wdV0wf5z+zx qiQmgxad4cDUZqY7ZBjSrgI++T+jwe9CYwuzawUU= Received: by mx.zohomail.com with SMTPS id 1751771202980263.4048949758843; Sat, 5 Jul 2025 20:06:42 -0700 (PDT) From: Li Chen To: Li Chen ," Thomas Gleixner "," Ingo Molnar "," Borislav Petkov "," Dave Hansen ",," H . Peter Anvin "," Rafael J . Wysocki "," Peter Zijlstra "," Sohil Mehta "," Brian Gerst "," Patryk Wlazlyn " , linux-kernel@vger.kernel.org Subject: [PATCH v4 0/4] x86/smpboot: tidy sched-topology and drop useless SMT level Date: Sun, 6 Jul 2025 11:06:28 +0800 Message-ID: <20250706030636.397197-1-me@linux.beauty> X-Mailer: git-send-email 2.49.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-ZohoMailClient: External From: Li Chen This series cleans up sched-domain topology handling and eliminates hundreds of pointless attach/destroy cycles for large machines when SMT is not available. Patch 1, 2, and 3 do some cleanup and refactor. Patch 4 is a follow-up that simply skip SMT domain when cpu_smt_num_threads <= 1, so the SMT level never gets created. Tested on Qemu. changelog: v2: fix wording issue as suggested by Thomas [1] v3: remove pointless memset and adjust PKG index accordingly, as suggested by Thomas [2], and refine some other wording issues. v4: v4: Split refactor patche into three parts (as suggested by Peter [3]) and refined patch 4 logic (as done by K. [4]). [1]: https://lore.kernel.org/all/87msa2r018.ffs@tglx/ [2]: https://lore.kernel.org/all/875xglntx1.ffs@tglx/ [3]: https://lkml.org/lkml/2025/6/25/584 [4]: https://lore.kernel.org/lkml/1b706790-2fec-4582-a425-55eeff36c32e@amd.com/ Li Chen (4): smpboot: introduce SDTL() helper to tidy sched topology setup x86/smpboot: remove redundant CONFIG_SCHED_SMT x86/smpboot: moves x86_topology to static initialize and truncate x86/smpboot: avoid SMT domain attach/destroy if SMT is not enabled arch/powerpc/kernel/smp.c | 34 ++++++++------------- arch/s390/kernel/topology.c | 10 +++---- arch/x86/kernel/smpboot.c | 55 ++++++++++++++++------------------ include/linux/sched/topology.h | 6 ++-- kernel/sched/topology.c | 16 ++++------ 5 files changed, 53 insertions(+), 68 deletions(-) -- 2.49.0