From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932297AbbFLXvl (ORCPT ); Fri, 12 Jun 2015 19:51:41 -0400 Received: from mail.kernel.org ([198.145.29.136]:45068 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932088AbbFLXmY (ORCPT ); Fri, 12 Jun 2015 19:42:24 -0400 From: Andy Lutomirski To: x86@kernel.org Cc: Borislav Petkov , Peter Zijlstra , John Stultz , linux-kernel@vger.kernel.org, Len Brown , Huang Rui , Denys Vlasenko , Andy Lutomirski Subject: [PATCH 06/17] x86/tsc: Use the full 64-bit tsc in tsc_delay Date: Fri, 12 Jun 2015 16:41:40 -0700 Message-Id: X-Mailer: git-send-email 2.4.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As a very minor optimization, tsc_delay was only using the low 32 bits of the TSC. It's a delay function, so just use the whole thing. Signed-off-by: Andy Lutomirski --- arch/x86/lib/delay.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/lib/delay.c b/arch/x86/lib/delay.c index 9a52ad0c0758..35115f3786a9 100644 --- a/arch/x86/lib/delay.c +++ b/arch/x86/lib/delay.c @@ -49,16 +49,16 @@ static void delay_loop(unsigned long loops) /* TSC based delay: */ static void delay_tsc(unsigned long __loops) { - u32 bclock, now, loops = __loops; + u64 bclock, now, loops = __loops; int cpu; preempt_disable(); cpu = smp_processor_id(); rdtsc_barrier(); - rdtscl(bclock); + bclock = native_read_tsc(); for (;;) { rdtsc_barrier(); - rdtscl(now); + now = native_read_tsc(); if ((now - bclock) >= loops) break; @@ -80,7 +80,7 @@ static void delay_tsc(unsigned long __loops) loops -= (now - bclock); cpu = smp_processor_id(); rdtsc_barrier(); - rdtscl(bclock); + bclock = native_read_tsc(); } } preempt_enable(); -- 2.4.2