Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756548AbbKRSrk (ORCPT ); Wed, 18 Nov 2015 13:47:40 -0500 Received: from foss.arm.com ([217.140.101.70]:36545 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754016AbbKRSrj (ORCPT ); Wed, 18 Nov 2015 13:47:39 -0500 Date: Wed, 18 Nov 2015 18:47:36 +0000 From: Will Deacon To: Yang Shi Cc: Catalin.Marinas@arm.com, 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 Message-ID: <20151118184736.GM1588@arm.com> References: <1447870505-19319-1-git-send-email-yang.shi@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1447870505-19319-1-git-send-email-yang.shi@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2782 Lines: 84 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. 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); > + > /* > * Dump out the common processor features in a single line. > * Userspace should read the hwcaps with getauxval(AT_HWCAP) > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c > index b1adc51..1bed772 100644 > --- a/arch/arm64/kernel/smp.c > +++ b/arch/arm64/kernel/smp.c > @@ -326,7 +326,12 @@ static void __init hyp_mode_check(void) > > void __init smp_cpus_done(unsigned int max_cpus) > { > - pr_info("SMP: Total of %d processors activated.\n", num_online_cpus()); > + unsigned long bogosum = loops_per_jiffy * num_online_cpus(); > + > + pr_info("SMP: Total of %d processors activated (%lu.%02lu BogoMIPS).\n", > + num_online_cpus(), bogosum / (500000/HZ), > + (bogosum / (5000/HZ)) % 100); Can we drop this hunk? I don't see a pressing need to print this in dmesg. With those two changes: Acked-by: Will Deacon I guess this needs Cc'ing to stable, too. Thanks, Will -- 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/