From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Date: Thu, 25 Nov 2010 22:06:12 -0600 From: Olof Johansson Subject: Re: [PATCH v2] Add call to non-crashing cores through IPI Message-ID: <20101126040612.GA6598@lixom.net> References: <1290587308-22038-1-git-send-email-per.xx.fransson@stericsson.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1290587308-22038-1-git-send-email-per.xx.fransson@stericsson.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Per Fransson Cc: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org Hi, Just a couple of nitpicks below. It's also common to prefix the patch subject with the subsystem (i.e. "ARM: kexec: ...") -Olof On Wed, Nov 24, 2010 at 09:28:28AM +0100, Per Fransson wrote: > v2 changes: > * the interrupts of the calling core are no longer disabled > before performing the IPI > --- > > When kexec is used to start a crash kernel the other cores > are notified. These non-crashing cores will save their state > in the crash notes and then do nothing. > > Signed-off-by: Per Fransson > --- > arch/arm/kernel/machine_kexec.c | 27 +++++++++++++++++++++++++++ > 1 files changed, 27 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c > index 3a8fd51..57a7f2f 100644 > --- a/arch/arm/kernel/machine_kexec.c > +++ b/arch/arm/kernel/machine_kexec.c > @@ -23,6 +23,8 @@ extern unsigned long kexec_indirection_page; > extern unsigned long kexec_mach_type; > extern unsigned long kexec_boot_atags; > > +static atomic_t waiting_for_crash_ipi; > + > /* > * Provide a dummy crash_notes definition while crash dump arrives to arm. > * This prevents breakage of crash_notes attribute in kernel/ksysfs.c. > @@ -37,9 +39,34 @@ void machine_kexec_cleanup(struct kimage *image) > { > } > > +void machine_crash_nonpanic_core(void *unused) > +{ > + struct pt_regs regs; > + > + crash_setup_regs(®s, NULL); > + printk(KERN_EMERG "CPU %u will stop doing anything useful since another CPU has crashed\n", > + smp_processor_id()); No other architecture has verbose output like this. Maybe lower it to KERN_DEBUG if you feel it's needed on a production kernel? > + crash_save_cpu(®s, smp_processor_id()); > + flush_cache_all(); > + > + atomic_dec(&waiting_for_crash_ipi); > + while (1) > + cpu_relax(); > +} > + > void machine_crash_shutdown(struct pt_regs *regs) > { > + unsigned long msecs; Int should be enough here? Not that it makes a difference on ARM, but anyway. :) > + > local_irq_disable(); > + > + atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); > + smp_call_function(machine_crash_nonpanic_core, NULL, false); > + msecs = 1000; /* Wait at most a second for the other cpus to stop */ > + while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { > + mdelay(1); > + msecs--; > + } If anything, logging here if not all cpus were stopped would be more useful. > crash_save_cpu(regs, smp_processor_id()); > > printk(KERN_INFO "Loading crashdump kernel...\n"); _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec