From: Li Chen <me@linux.beauty>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Sohil Mehta <sohil.mehta@intel.com>,
Brian Gerst <brgerst@gmail.com>,
Patryk Wlazlyn <patryk.wlazlyn@linux.intel.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH v3 0/2] x86/smpboot: tidy sched-topology and drop useless SMT level
Date: Wed, 25 Jun 2025 11:45:48 +0800 [thread overview]
Message-ID: <20250625034552.42365-1-me@linux.beauty> (raw)
From: Li Chen <chenl311@chinatelecom.cn>
This two–patch 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 (from Thomas, unchanged) gets rid of the #ifdef maze in
build_sched_topology() by statically initialising the topology array.
Patch 2 (mine) is a follow-up that simply memmoves the array when
cpu_smt_num_threads <= 1, so the SMT level never gets created and
immediately torn down again.
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.
[1]: https://lore.kernel.org/all/87msa2r018.ffs@tglx/
[2]: https://lore.kernel.org/all/875xglntx1.ffs@tglx/
Li Chen (1):
x86/smpboot: avoid SMT domain attach/destroy if SMT is not enabled
Thomas Gleixner (1):
x86/smpboot: Decrapify build_sched_topology()
arch/x86/kernel/smpboot.c | 59 +++++++++++++++++++++------------------
1 file changed, 32 insertions(+), 27 deletions(-)
--
2.49.0
next reply other threads:[~2025-06-25 3:46 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-25 3:45 Li Chen [this message]
2025-06-25 3:45 ` [PATCH v3 1/2] x86/smpboot: Decrapify build_sched_topology() Li Chen
2025-06-25 8:28 ` Peter Zijlstra
2025-06-30 0:21 ` Li Chen
2025-06-30 12:56 ` Thomas Gleixner
2025-06-25 3:45 ` [PATCH v3 2/2] x86/smpboot: avoid SMT domain attach/destroy if SMT is not enabled Li Chen
2025-06-25 5:45 ` K Prateek Nayak
2025-06-25 8:30 ` Peter Zijlstra
2025-06-30 0:39 ` Li Chen
2025-06-25 8:29 ` Peter Zijlstra
2025-06-30 0:29 ` Li Chen
2025-06-25 5:50 ` [PATCH v3 0/2] x86/smpboot: tidy sched-topology and drop useless SMT level K Prateek Nayak
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