From patchwork Wed May 28 12:53:13 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 893531 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) (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 E9572214211; Wed, 28 May 2025 12:55:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=79.96.170.134 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748436916; cv=none; b=oN4wG9okM4XejT7Nj/j++D52dHxWTJ75RDze2Z8sLcPJpyY4pOeyIKkmkpu5xKjybWHjxLnTmaYl2v4rokPb8jAIQPx7x+uIC1r/Tlbpp6zY8fqweQVuvjyMnpyYdaylwXi0wAau0+ft8Vqw/LO2H6+JZHl6KoeTJzUhzBpS6r8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748436916; c=relaxed/simple; bh=u06uU+f22ZydMweS4ad4ipwJZCaFj54prJ9Y8i2zNxA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=mBLvBUyjYWfZVef32EbL5fRmd0nHV0u+VnqgbHDqJxFWvArRssYgLl7z8ag9ZDUh1i4kIzWdDVkT0hhuFXMOtPmg0V5fwDQEMOq32rjOnAUzyQkqxMTAHRW1/6ZJw2BoEjqdgARtBHqOWcxAghOVPE9MQI2L9sIhM0ZV32AXDB8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net; spf=pass smtp.mailfrom=rjwysocki.net; dkim=pass (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b=ndnJc5FP; arc=none smtp.client-ip=79.96.170.134 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b="ndnJc5FP" Received: from kreacher.localnet (unknown [5.63.189.50]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by cloudserver094114.home.pl (Postfix) with ESMTPSA id 6D2D166810C; Wed, 28 May 2025 14:55:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rjwysocki.net; s=dkim; t=1748436904; bh=u06uU+f22ZydMweS4ad4ipwJZCaFj54prJ9Y8i2zNxA=; h=From:Subject:Date; b=ndnJc5FPKZ/gAEhXWrUWuQ6N9zgrgwaDt4sG1DWP0owFVQwK1CZf7V3HCLkv2cHX2 Vpud6wmvofFI8Oj6VQryqoPqtveIFlwXF6gBVPfR9m0i0XuxdjgA/L4yVB2OxZ/alm uGdy/tdhka3APiXK2yPQIWaQf6BkyPiQsNrvicF3jeSY/WgCVAw9vNb/0Qpz6grmvn uEZJNphV2DHygPhapge0M1qhWVO4Pv6egj76Vf7Mr2n+VgT4HfVLGYOISquf4OqYEL g2QNMwFWsEV0YVZPoJcrfoiZ70lJTSx3zhosD8y2QYFxXAbmXtuZES0XRjfJsAiANR opTZ0doBCBCpA== From: "Rafael J. Wysocki" To: x86 Maintainers Cc: LKML , Linux PM , Len Brown , Peter Zijlstra , Thomas Gleixner , Borislav Petkov , Dave Hansen , Artem Bityutskiy , "Gautham R. Shenoy" , Ingo Molnar , Todd Brandt Subject: [PATCH v1 0/2] x86/smp: Fix power regression introduced by commit 96040f7273e2 Date: Wed, 28 May 2025 14:53:13 +0200 Message-ID: <2006806.PYKUYFuaPT@rjwysocki.net> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CLIENT-IP: 5.63.189.50 X-CLIENT-HOSTNAME: 5.63.189.50 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: 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 X-DCC--Metrics: v370.home.net.pl 1024; Body=12 Fuz1=12 Fuz2=12 Hi Everyone, Commit 96040f7273e2 ("x86/smp: Eliminate mwait_play_dead_cpuid_hint()") that shipped in 6.15 introduced a nasty power regression on systems that start with "nosmt" in the kernel command line which prevents it from entering deep package idle states (for instance, PC10) later on. Idle power, including power in suspend-to-idle, goes up significantly on those systems as a result. Address this by reverting commit 96040f7273e2 (patch [1/2]) and using a different approach, which is to retain mwait_play_dead_cpuid_hint() and still prefer it to hlt_play_dead() in case it is needed when cpuidle is not available, but prefer cpuidle_play_dead() to it by default (patch [2/2]). Thanks!