| Message ID | 5BDBB6FF.6080907@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] ARM:kexec:offline panic_smp_self_stop CPU | expand |
On Fri, Nov 02, 2018 at 10:31:27AM +0800, wangyufen wrote: > In case panic() and panic() called at the same time on different CPUS. > For example: > CPU 0: > panic() > __crash_kexec > machine_crash_shutdown > crash_smp_send_stop > machine_kexec > BUG_ON(num_online_cpus() > 1); > > CPU 1: > panic() > local_irq_disable > panic_smp_self_stop > > If CPU 1 calls panic_smp_self_stop() before crash_smp_send_stop(), kdump > fails. CPU1 can't receive the ipi irq, CPU1 will be always online. > To fix this problem, this patch split out the panic_smp_self_stop() > and add set_cpu_online(smp_processor_id(), false). Looks fine now, please send it to the patch system (details in my signature.) Thanks. > > Signed-off-by: Yufen Wang <wangyufen@huawei.com> > --- > arch/arm/kernel/smp.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c > index 9000d8b..d7b86e4 100644 > --- a/arch/arm/kernel/smp.c > +++ b/arch/arm/kernel/smp.c > @@ -682,6 +682,21 @@ void smp_send_stop(void) > pr_warn("SMP: failed to stop secondary CPUs\n"); > } > > +/* In case panic() and panic() called at the same time on CPU1 and CPU2, > + * and CPU 1 calls panic_smp_self_stop() before crash_smp_send_stop() > + * CPU1 can't receive the ipi irqs from CPU2, CPU1 will be always online, > + * kdump fails. So split out the panic_smp_self_stop() and add > + * set_cpu_online(smp_processor_id(), false). > + */ > +void panic_smp_self_stop(void) > +{ > + pr_debug("CPU %u will stop doing anything useful since another CPU has paniced\n", > + smp_processor_id()); > + set_cpu_online(smp_processor_id(), false); > + while (1) > + cpu_relax(); > +} > + > /* > * not supported here > */ > -- > 2.7.4 > >
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 9000d8b..d7b86e4 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -682,6 +682,21 @@ void smp_send_stop(void) pr_warn("SMP: failed to stop secondary CPUs\n"); } +/* In case panic() and panic() called at the same time on CPU1 and CPU2, + * and CPU 1 calls panic_smp_self_stop() before crash_smp_send_stop() + * CPU1 can't receive the ipi irqs from CPU2, CPU1 will be always online, + * kdump fails. So split out the panic_smp_self_stop() and add + * set_cpu_online(smp_processor_id(), false). + */ +void panic_smp_self_stop(void) +{ + pr_debug("CPU %u will stop doing anything useful since another CPU has paniced\n", + smp_processor_id()); + set_cpu_online(smp_processor_id(), false); + while (1) + cpu_relax(); +} + /* * not supported here */
In case panic() and panic() called at the same time on different CPUS. For example: CPU 0: panic() __crash_kexec machine_crash_shutdown crash_smp_send_stop machine_kexec BUG_ON(num_online_cpus() > 1); CPU 1: panic() local_irq_disable panic_smp_self_stop If CPU 1 calls panic_smp_self_stop() before crash_smp_send_stop(), kdump fails. CPU1 can't receive the ipi irq, CPU1 will be always online. To fix this problem, this patch split out the panic_smp_self_stop() and add set_cpu_online(smp_processor_id(), false). Signed-off-by: Yufen Wang <wangyufen@huawei.com> --- arch/arm/kernel/smp.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)