From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH v3 4/4] nmi_backtrace: generate one-line reports for idle cpus Date: Tue, 22 Mar 2016 23:31:11 +0100 Message-ID: <54039485.X1biSGXPBa@vostro.rjw.lan> References: <1458667179-19630-1-git-send-email-cmetcalf@mellanox.com> <1458667179-19630-5-git-send-email-cmetcalf@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: Received: from v094114.home.net.pl ([79.96.170.134]:61129 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752156AbcCVW3B (ORCPT ); Tue, 22 Mar 2016 18:29:01 -0400 In-Reply-To: <1458667179-19630-5-git-send-email-cmetcalf@mellanox.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Chris Metcalf Cc: Peter Zijlstra , Russell King , Thomas Gleixner , Aaron Tomlin , Ingo Molnar , Andrew Morton , Daniel Thompson , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org On Tuesday, March 22, 2016 01:19:39 PM Chris Metcalf wrote: > When doing an nmi backtrace of many cores, most of which are idle, > the output is a little overwhelming and very uninformative. Suppress > messages for cpus that are idling when they are interrupted and just > emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN". > > We do this by grouping all the cpuidle code together into a new > .cpuidle.text section, and then checking the address of the > interrupted PC to see if it lies within that section. > > This commit suitably tags x86, arm64, and tile idle routines, > and only adds in the minimal framework for other architectures. > > Acked-by: Peter Zijlstra (Intel) > Tested-by: Peter Zijlstra (Intel) > Signed-off-by: Chris Metcalf > --- [cut] > diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c > index cd4510a63375..924554f920fb 100644 > --- a/drivers/idle/intel_idle.c > +++ b/drivers/idle/intel_idle.c > @@ -725,8 +725,8 @@ static struct cpuidle_state avn_cstates[] = { > * > * Must be called under local_irq_disable(). > */ > -static int intel_idle(struct cpuidle_device *dev, > - struct cpuidle_driver *drv, int index) > +static __cpuidle int intel_idle(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, int index) > { > unsigned long ecx = 1; /* break on interrupt flag */ > struct cpuidle_state *state = &drv->states[index]; Well, what about intel_idle_freeze()? Or do we not care? And analogous stuff in processor_idle.c for that matter? acpi_idle_enter()/acpi_idle_enter_freeze() plus stuff called by those? Thanks, Rafael