From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 32A153A7F7C for ; Tue, 24 Feb 2026 16:36:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771950988; cv=none; b=Z/yASw365VHT8eoR6KzvsC55tTiDMcsL8NkBPCvPfPdDsQA8lJIDiGUoGu3bXG7lPalvzYslsKAK1aX5IrSz1KyQASUzIiqLAJK/VFGT4tP9qImCKg2xnqzyaYZsQ7OPkETcsOYDhMRUMBIvmgQAGoPXNwFfq4iwSCgid2UBmEg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771950988; c=relaxed/simple; bh=Dnjjqe21GBxvZ5X+pDOO1X6vhlAY3v8cSHNjce7QgVM=; h=Date:Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=A6jUrc115DqunNjmt9UAzzDKAcSbLc+wCpUkEncRE1y4FD/BlR0x1q7EG999zvDJ7gmbpjOR6EJuCHVOpwMTC33NCBFxH1RsgxZKDSxcP2bCRHDzeKIm3hX7kAyGvUJ6TMmJwtMWVJ+vzB+tNNRIJ2ROTnmSBHI8sE4lqLHjdvc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nh2ZL69K; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nh2ZL69K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80865C116D0; Tue, 24 Feb 2026 16:36:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771950988; bh=Dnjjqe21GBxvZ5X+pDOO1X6vhlAY3v8cSHNjce7QgVM=; h=Date:From:To:Cc:Subject:References:From; b=nh2ZL69K4D/Mq/cCjA2nlvoXRog9VRE9t8OaIwBt/EmLyxJP9Zz1w1L2IK49G8ek6 ywZ6iqNmDTxIiVUukneZjeXnwG8mW/of68IaiLm5/GH0U6uBTFeX0cC3xuEaCEdceK lppnPmMCaKSD316ZNoaRd73XntemV8jZW7TEm6l5tr3/BiRB3Wod6XgICtWGk/FybI vJECXYFYEQO25xbzRKD+/VD+AyMlKjX+eYILVh8q6H6/dVfULb4cIj4038ReWgzbWm C2enDkvRHxQweWXwneMoeLCg2lgjqc1YTr3Cnko/BnQ++yuyZz/dkKnfWKhAq8wwEv UzZTxygEmnLkA== Date: Tue, 24 Feb 2026 17:36:24 +0100 Message-ID: <20260224163429.741886362@kernel.org> User-Agent: quilt/0.68 From: Thomas Gleixner To: LKML Cc: Anna-Maria Behnsen , John Stultz , Stephen Boyd , Daniel Lezcano , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , x86@kernel.org, Peter Zijlstra , Frederic Weisbecker , Eric Dumazet Subject: [patch 15/48] x86: Inline TSC reads in timekeeping References: <20260224163022.795809588@kernel.org> 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 Avoid the overhead of the indirect call for a single instruction to read the TSC. Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig | 1 + arch/x86/include/asm/clock_inlined.h | 14 ++++++++++++++ arch/x86/kernel/tsc.c | 1 + 3 files changed, 16 insertions(+) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -141,6 +141,7 @@ config X86 select ARCH_USE_SYM_ANNOTATIONS select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 + select ARCH_WANTS_CLOCKSOURCE_READ_INLINE if X86_64 select ARCH_WANTS_DYNAMIC_TASK_STRUCT select ARCH_WANTS_NO_INSTR select ARCH_WANT_GENERAL_HUGETLB --- /dev/null +++ b/arch/x86/include/asm/clock_inlined.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_CLOCK_INLINED_H +#define _ASM_X86_CLOCK_INLINED_H + +#include + +struct clocksource; + +static __always_inline u64 arch_inlined_clocksource_read(struct clocksource *cs) +{ + return (u64)rdtsc_ordered(); +} + +#endif --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1201,6 +1201,7 @@ static struct clocksource clocksource_ts .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES | + CLOCK_SOURCE_CAN_INLINE_READ | CLOCK_SOURCE_MUST_VERIFY | CLOCK_SOURCE_VERIFY_PERCPU, .id = CSID_X86_TSC,