Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757203AbbKRVzP (ORCPT ); Wed, 18 Nov 2015 16:55:15 -0500 Received: from mail-qg0-f53.google.com ([209.85.192.53]:35104 "EHLO mail-qg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755389AbbKRVzN (ORCPT ); Wed, 18 Nov 2015 16:55:13 -0500 Date: Wed, 18 Nov 2015 16:55:10 -0500 (EST) From: Nicolas Pitre To: Will Deacon cc: Yang Shi , Catalin Marinas , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org Subject: Re: [PATCH] arm64: restore bogomips information in /proc/cpuinfo In-Reply-To: <20151118184736.GM1588@arm.com> Message-ID: References: <1447870505-19319-1-git-send-email-yang.shi@linaro.org> <20151118184736.GM1588@arm.com> User-Agent: Alpine 2.20 (LFD 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2248 Lines: 67 On Wed, 18 Nov 2015, Will Deacon wrote: > Hello, > > On Wed, Nov 18, 2015 at 10:15:05AM -0800, Yang Shi wrote: > > As what Pavel Machek reported [1], some userspace applications depend on > > bogomips showed by /proc/cpuinfo. > > > > Although there is much less legacy impact on aarch64 than arm, but it does > > break libvirt. > > > > Basically, this patch reverts commit 326b16db9f69fd0d279be873c6c00f88c0a4aad5 > > ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo"), but with > > some tweak due to context change. > > > > [1] https://lkml.org/lkml/2015/1/4/132 > > I lost this argument last time around, so I won't re-tread that path this > time around. No kidding. ;-) > I do, however, have some comments on the patch. > > > > > Signed-off-by: Yang Shi > > --- > > arch/arm64/kernel/cpuinfo.c | 5 +++++ > > arch/arm64/kernel/smp.c | 7 ++++++- > > 2 files changed, 11 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c > > index 706679d..8d4ba77 100644 > > --- a/arch/arm64/kernel/cpuinfo.c > > +++ b/arch/arm64/kernel/cpuinfo.c > > @@ -30,6 +30,7 @@ > > #include > > #include > > #include > > +#include > > > > /* > > * In case the boot CPU is hotpluggable, we record its initial state and > > @@ -112,6 +113,10 @@ static int c_show(struct seq_file *m, void *v) > > */ > > seq_printf(m, "processor\t: %d\n", i); > > > > + seq_printf(m, "BogoMIPS\t: %lu.%02lu\n\n", > > This double newline makes /proc/cpuinfo looks really odd. Can we just > have one, please? > > > + loops_per_jiffy / (500000UL/HZ), > > + loops_per_jiffy / (5000UL/HZ) % 100); Also, given nobody ever relied on any prior value here, can we at least print something here with some semblance of a meaning i.e. something related to the actual CPU speed and not some separate useless constant timer clock please? Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/