From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755244Ab1B1QhB (ORCPT ); Mon, 28 Feb 2011 11:37:01 -0500 Received: from kroah.org ([198.145.64.141]:41198 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755226Ab1B1Qg7 (ORCPT ); Mon, 28 Feb 2011 11:36:59 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Mon Feb 28 08:24:06 2011 Message-Id: <20110228162406.554108148@clark.kroah.org> User-Agent: quilt/0.48-11.2 Date: Mon, 28 Feb 2011 08:22:30 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Shaohua Li , venkatesh.pallipadi@intel.com, Ingo Molnar , Thomas Renninger Subject: [09/68] x86, hpet: Disable per-cpu hpet timer if ARAT is supported In-Reply-To: <20110228163502.GA27221@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Shaohua Li commit 39fe05e58c5e448601ce46e6b03900d5bf31c4b0 upstream. If CPU support always running local APIC timer, per-cpu hpet timer could be disabled, which is useless and wasteful in such case. Let's leave the timers to others. The effect is that we reserve less timers. Signed-off-by: Shaohua Li Cc: venkatesh.pallipadi@intel.com LKML-Reference: <20090812031612.GA10062@sli10-desk.sh.intel.com> Signed-off-by: Ingo Molnar Cc: Thomas Renninger Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/hpet.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -606,6 +606,8 @@ static void hpet_msi_capability_lookup(u if (hpet_msi_disable) return; + if (boot_cpu_has(X86_FEATURE_ARAT)) + return; id = hpet_readl(HPET_ID); num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT); @@ -894,10 +896,8 @@ int __init hpet_enable(void) if (id & HPET_ID_LEGSUP) { hpet_legacy_clockevent_register(); - hpet_msi_capability_lookup(2); return 1; } - hpet_msi_capability_lookup(0); return 0; out_nohpet: @@ -930,12 +930,20 @@ static __init int hpet_late_init(void) if (!hpet_virt_address) return -ENODEV; + if (hpet_readl(HPET_ID) & HPET_ID_LEGSUP) + hpet_msi_capability_lookup(2); + else + hpet_msi_capability_lookup(0); + hpet_reserve_platform_timers(hpet_readl(HPET_ID)); hpet_print_config(); if (hpet_msi_disable) return 0; + if (boot_cpu_has(X86_FEATURE_ARAT)) + return 0; + for_each_online_cpu(cpu) { hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu); }