On Fri, Apr 15, 2016 at 12:24:36PM +0200, Jan Glauber wrote: > When CPUs are stopped during an abnormal operation like panic > for each CPU a line is printed and the stack trace is dumped. > > This information is only interesting for the aborting CPU > and on systems with many CPUs it only makes it harder to > debug if after the aborting CPU the log is flooded with data > about all other CPUs too. > > Therefore remove the stack dump and printk of other CPUs > and only print a single line that the other CPUs are going to be > stopped. > > Signed-off-by: Jan Glauber <[email protected]> > --- > arch/arm64/kernel/smp.c | 11 +++-------- > 1 file changed, 3 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c > index b2d5f4e..e6c2eb1 100644 > --- a/arch/arm64/kernel/smp.c > +++ b/arch/arm64/kernel/smp.c > @@ -770,14 +770,6 @@ static DEFINE_RAW_SPINLOCK(stop_lock); > */ > static void ipi_cpu_stop(unsigned int cpu) > { > - if (system_state == SYSTEM_BOOTING || > - system_state == SYSTEM_RUNNING) { > - raw_spin_lock(&stop_lock); > - pr_crit("CPU%u: stopping\n", cpu); > - dump_stack(); > - raw_spin_unlock(&stop_lock); > - } > - > set_cpu_online(cpu, false); > > local_irq_disable(); > @@ -872,6 +864,9 @@ void smp_send_stop(void) > cpumask_copy(&mask, cpu_online_mask); > cpumask_clear_cpu(smp_processor_id(), &mask); > > + if (system_state == SYSTEM_BOOTING || > + system_state == SYSTEM_RUNNING) > + pr_crit("SMP: stopping secondary CPUs\n");
You can remove stop_lock altogether now, right? I also wonder whether it would be worth printing out which CPUs are still online in the case where we fail to stop all the secondaries? Will
