From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [PATCH 2/2 v2] x86 idle: remove 32-bit-only "no-hlt" parameter, hlt_works_ok flag Date: Sun, 10 Feb 2013 23:26:18 +0100 Message-ID: <20130210222618.GA2573@pd.tnic> References: <1360483829-16349-1-git-send-email-lenb@kernel.org> <51181317.1080905@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail.skyhub.de ([78.46.96.112]:60554 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756765Ab3BJW0W (ORCPT ); Sun, 10 Feb 2013 17:26:22 -0500 Content-Disposition: inline In-Reply-To: <51181317.1080905@kernel.org> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Len Brown Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Len Brown , x86@kernel.org, "H. Peter Anvin" On Sun, Feb 10, 2013 at 04:37:27PM -0500, Len Brown wrote: > From: Len Brown >=20 > Remove 32-bit x86 a cmdline param "no-hlt", > and the cpuinfo_x86.hlt_works_ok that it sets. >=20 > If a user wants to avoid HLT, then "idle=3Dpoll" > is much more useful, as it avoids invocation of HLT > in idle, while "no-hlt" failed to do so. >=20 > Indeed, hlt_works_ok was consulted in only 3 places. >=20 > First, in /proc/cpuinfo where "hlt_bug yes" > would be printed if and only if the user booted > the system with "no-hlt" -- as there was no other code > to set that flag. >=20 > Second, check_hlt() would not invoke halt() if "no-hlt" > were on the cmdline. >=20 > Third, it was consulted in stop_this_cpu(), which is invoked > by native_machine_halt()/reboot_interrupt()/smp_stop_nmi_callback() -= - > all cases where the machine is being shutdown/reset. > The flag was not consulted in the more frequently invoked > play_dead()/hlt_play_dead() used in processor offline and suspend. >=20 > Since Linux-3.0 there has been a run-time notice upon "no-hlt" invoca= tions > indicating that it would be removed in 2012. >=20 > Signed-off-by: Len Brown > Cc: x86@kernel.org > --- > v2: remove also check_hlt() [ =E2=80=A6 ] > diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c > index 3286a92..e280253 100644 > --- a/arch/x86/kernel/cpu/proc.c > +++ b/arch/x86/kernel/cpu/proc.c > @@ -28,7 +28,6 @@ static void show_cpuinfo_misc(struct seq_file *m, s= truct cpuinfo_x86 *c) > { > seq_printf(m, > "fdiv_bug\t: %s\n" > - "hlt_bug\t\t: %s\n" Are we fine with changing /proc/cpuinfo output? We tend to consider it an API to userspace, judging by past experience... --=20 Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --