From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VflNf-0006RD-OR for kexec@lists.infradead.org; Mon, 11 Nov 2013 06:53:53 +0000 Date: Mon, 11 Nov 2013 14:52:50 +0800 From: Baoquan He Subject: Re: [PATCH] x86: make reboot task only run on the appropriate processor Message-ID: <20131111065250.GA31206@dhcp-16-252.nay.redhat.com> References: <1383642967-12595-1-git-send-email-bhe@redhat.com> <20131108151416.GA13068@redhat.com> <20131110094425.GA17965@dhcp-16-252.nay.redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20131110094425.GA17965@dhcp-16-252.nay.redhat.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" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Vivek Goyal Cc: Robin Holt , mwhitehe@redhat.com, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Robin Holt , davej@fedoraproject.org, mingo@redhat.com, "Eric W. Biederman" , hpa@zytor.com, rmk+kernel@arm.linux.org.uk, tglx@linutronix.de, akpm@linux-foundation.org, chaowang@redhat.com On 11/10/13 at 05:44pm, Baoquan He wrote: > On 11/08/13 at 10:14am, Vivek Goyal wrote: > > On Tue, Nov 05, 2013 at 05:16:07PM +0800, Baoquan He wrote: > > > > > Hi Bao, > > > > This patch fixes the issue for me too. I noticed that we have generic > > function migrate_to_reboot_cpu() to achieve what we want and rest of > > the reboot paths are using it. So how about using that function. I > > wrote the new patch below. It works for me. Can you please give it > > a try. Hi Vivek, Your patch works, my test script has wrong typo. Baoquan Thanks a lot > > Seems there's something wrong with this function, that error happened > when I executed the 2nd "kexec -e". That means executing "kexec -e" in > kexec-ed kernel. > > Tomorrow I will ask people around take more tests. We need set affinity > to test this. E.g always execute : > > taskset -c 1 -sh "kexec -e" > > > > > > Thanks > > Vivek > > > > kexec: migrate to reboot cpu > > > > Commit 1b3a5d02ee070c8f9943333b9b6370f486601e0f moved reboot= handling to > > generic code. In the process it also removed the code in > > native_machine_shutdown() which are moving reboot process to reboot_cpu/cpu0. > > > > I guess that thought must have been that all reboot paths are calling > > migrate_to_reboot_cpu(), so we don't need this special handling. But > > kexec reboot path (kernel_kexec()) is not calling migrate_to_reboot_cpu() > > so above change broke kexec. Now reboot can happen on non-boot cpu and when > > INIT is sent in second kerneo to bring up BP, it brings down the machine. > > > > So start calling migrate_to_reboot_cpu() in kexec reboot path to avoid > > this problem. > > > > Reported-by: Matthew Whitehead > > Reported-by: Dave Young > > Signed-off-by: Vivek Goyal > > --- > > include/linux/reboot.h | 1 + > > kernel/kexec.c | 1 + > > kernel/reboot.c | 2 +- > > 3 files changed, 3 insertions(+), 1 deletion(-) > > > > Index: linux-2.6/kernel/reboot.c > > =================================================================== > > --- linux-2.6.orig/kernel/reboot.c 2013-10-16 00:30:50.000000000 -0400 > > +++ linux-2.6/kernel/reboot.c 2013-11-08 21:31:03.379064848 -0500 > > @@ -104,7 +104,7 @@ int unregister_reboot_notifier(struct no > > } > > EXPORT_SYMBOL(unregister_reboot_notifier); > > > > -static void migrate_to_reboot_cpu(void) > > +void migrate_to_reboot_cpu(void) > > { > > /* The boot cpu is always logical cpu 0 */ > > int cpu = reboot_cpu; > > Index: linux-2.6/include/linux/reboot.h > > =================================================================== > > --- linux-2.6.orig/include/linux/reboot.h 2013-11-08 21:33:27.000000000 -0500 > > +++ linux-2.6/include/linux/reboot.h 2013-11-08 21:34:29.778073522 -0500 > > @@ -43,6 +43,7 @@ extern int unregister_reboot_notifier(st > > * Architecture-specific implementations of sys_reboot commands. > > */ > > > > +extern void migrate_to_reboot_cpu(void); > > extern void machine_restart(char *cmd); > > extern void machine_halt(void); > > extern void machine_power_off(void); > > Index: linux-2.6/kernel/kexec.c > > =================================================================== > > --- linux-2.6.orig/kernel/kexec.c 2013-10-16 00:30:50.000000000 -0400 > > +++ linux-2.6/kernel/kexec.c 2013-11-08 21:34:02.492072375 -0500 > > @@ -1676,6 +1676,7 @@ int kernel_kexec(void) > > #endif > > { > > kernel_restart_prepare(NULL); > > + migrate_to_reboot_cpu(); > > printk(KERN_EMERG "Starting new kernel\n"); > > machine_shutdown(); > > } _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec