| Message ID | 1460715876-10780-1-git-send-email-jglauber@cavium.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 <jglauber@cavium.com> > --- > 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
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"); smp_cross_call(&mask, IPI_CPU_STOP); }
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 <jglauber@cavium.com> --- arch/arm64/kernel/smp.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-)