From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 6486E3FE658; Fri, 5 Jun 2026 05:41:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780638117; cv=none; b=pJK4EoMUiiPDQhL04rgF4Hh9zsaYO2Dv/O5t2ZZwSwSmv2fb0Aa5uDgbJSmipEZFGRJB47j89BwIbbJIldcm++Q5IwdS6PG9hA2YBxANYY/fqDpzYehvNnV7OLZON6ROjWnZQdFniQue7hWFLCwJN2jYxost9Ivk/9b0hJOgSAw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780638117; c=relaxed/simple; bh=1Z0r1dd+5UaBxiJIV7yyJHPW2au7yP4Ki/behDAnWqk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ng8yY9RsPixLkjkbm7gOgjEW30HrmjI4PUK10tzqaWaEBwVcykAZ+0U13AmUmcnJn37NGkTdUf7fA0EYeCdfrmUgTECn28/VpHPldGfWVb/HU+rrAeIKHvWnEuu0zsBt/Ml8KsLEWxbJQm74Cp63gBTC4Ue7/6KC9L+N3pye1po= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gi/kWcPB; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gi/kWcPB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A9C41F0089A; Fri, 5 Jun 2026 05:41:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780638115; bh=5fQe3JBbW1ecnzj9lOjL0hmTD9Wg7GMvup213RdzMTc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gi/kWcPBW3EaGbMHej9lPJNdHzD0aaT8t6m94Sjb60a27aJe7SiCne06Jsn+qxN96 37Y/n1XbOxEYpKdk49Ahtlzy2PwZ0iIpLwdYfYd8psvWHzyR8CEgchyzJPtRZvHS4r tIrYbyabjXurnV9xC63mXw5P0tsIRx+JcoMvwdpsep7j/w9zRYfFMO4AuLsmq2cgvv nBkwod7gMrEG8isIGul3Ofp7t9ajodlfFo/by06YuEXHLen9VPQtepXJiCal9ygT/G 8DlzVulejJ3igmv2NIcyt0Gtxy1ms1LGR2LOgAXAHlh3kiDSpks4jlsEamObzqj9xq E7FpkXeg/8QMg== Received: from phl-compute-08.internal (phl-compute-08.internal [10.202.2.48]) by mailfauth.phl.internal (Postfix) with ESMTP id C9C7CF40068; Fri, 5 Jun 2026 01:41:52 -0400 (EDT) Received: from phl-frontend-03 ([10.202.2.162]) by phl-compute-08.internal (MEProxy); Fri, 05 Jun 2026 01:41:52 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTFG0WJa+84B5ZLakFCJusLrHx60u/M2e4tgb8vvSWGQWHXMFZeKktHow9VrFaQhwL 60vkPLe/GHUXrF9uQjn9EtWhYCiYebO343SXKkauObGNd0gaHEDMGyAUdMEWI3xvV5+MXM Y5XIGIH+RCj/YpjPsc3XHQUzqyjdf8JDGbXE7uRDsVlh2adsQWoVoEG+11Li6tmpxBjo+n GbGHXxcMsG5BC+v/PWXz65OFiJmnJTn18gjrdwmPsAQA0I/XEj3HJhBv36WGSvCgORqSG4 pkDfFOinWXk05Px2n3ZYSDFusuNrnah7Cqk2jZsViR99U7a3ccatK3SGLf/zDxH9xSS8rM AOeG5ePFZZfA76kOVqoCfj7btvpGgV7BkafEpMDLqRqYQteE3BP+Zkc3tGEg6HKAx5ebSG +mfyKbfml1bRlYZdW9QkLLsmbzmqf4KpTRUTEWVFfODasljVxHQMv5gX9K8gy1vxzFXTaU cZCZZhuI5rcfutz0yazglWB3rJwiDthh8IdApnGVTsXOrx3v5UsJw77FXSlh9Kv42p15JE WawlWP7bZ34qpayMprYpdDmWSqEzyCJKbCu+zWYZNgKoMIsVhnPsVU7hmpSe6Ah/EF1PrW mwcS+qw7SgGtRJaM1gozqo5XbhQOYZn73l24WeQ/UR8UYb5mg5SORHHlOdLw X-ME-Proxy: Feedback-ID: i8dbe485b:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 5 Jun 2026 01:41:51 -0400 (EDT) From: Boqun Feng To: Peter Zijlstra Cc: Catalin Marinas , Will Deacon , Jonas Bonn , Stefan Kristiansson , Stafford Horne , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Arnd Bergmann , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Boqun Feng , Waiman Long , Andrew Morton , Andrii Nakryiko , Eduard Zingerman , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Kumar Kartikeya Dwivedi , Song Liu , Yonghong Song , Jiri Olsa , Shuah Khan , Miguel Ojeda , Gary Guo , =?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Jinjie Ruan , Lyude Paul , Thomas Huth , Sohil Mehta , Pawan Gupta , Sean Christopherson , Nikunj A Dadhania , "Xin Li (Intel)" , Joel Fernandes , Andy Shevchenko , Randy Dunlap , Yury Norov , Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-s390@vger.kernel.org, linux-arch@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, rust-for-linux@vger.kernel.org Subject: [PATCH v3 11/13] arm64: sched/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS Date: Thu, 4 Jun 2026 22:41:26 -0700 Message-ID: <20260605054128.5925-12-boqun@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260605054128.5925-1-boqun@kernel.org> References: <20260605054128.5925-1-boqun@kernel.org> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARM64 already uses 64bit preempt count and the need reschedule bit is maintained in a separate 32bit than the preempt count. Therefore preempt count has enough bits to represent 16 level of NMI nesting, hence enable it for ARM64. This saves a per-CPU variable and additional instructions in the NMI path. Signed-off-by: Boqun Feng --- arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index fe60738e5943..8178cb857115 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -248,6 +248,7 @@ config ARM64 select PCI_SYSCALL if PCI select POWER_RESET select POWER_SUPPLY + select HAS_SEPARATE_PREEMPT_RESCHED_BITS select SPARSE_IRQ select SWIOTLB select SYSCTL_EXCEPTION_TRACE -- 2.51.0