Revision f274ef8747d3be649bba8708696fb31cb00fa75a authored by Srivatsa S. Bhat on 21 May 2013, 09:32:48 UTC, committed by Benjamin Herrenschmidt on 31 May 2013, 22:29:27 UTC
Adam Lackorzynski reported the following build failure on !CONFIG_HOTPLUG_CPU configuration: CC arch/powerpc/kernel/rtas.o arch/powerpc/kernel/rtas.c: In function ‘rtas_cpu_state_change_mask’: arch/powerpc/kernel/rtas.c:843:4: error: implicit declaration of function ‘cpu_down’ [-Werror=implicit-function-declaration] cc1: all warnings being treated as errors make[1]: *** [arch/powerpc/kernel/rtas.o] Error 1 make: *** [arch/powerpc/kernel] Error 2 The build fails because cpu_down() is defined only under CONFIG_HOTPLUG_CPU. Looking further, the mobility code in pseries is one of the call-sites which uses rtas_ibm_suspend_me(), which in turn calls rtas_cpu_state_change_mask(). And the mobility code is unconditionally compiled-in (it does not fall under any Kconfig option). And commit 120496ac (powerpc: Bring all threads online prior to migration/hibernation) which introduced this build regression is critical for the proper functioning of the migration code. So it appears that the only solution to this problem is to enable CONFIG_HOTPLUG_CPU if SMP is enabled on PPC_PSERIES platforms. So make that change in the Kconfig. Reported-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de> Cc: stable@vger.kernel.org Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
1 parent 8e44ddc
timer_int.c
/**
* @file timer_int.c
*
* @remark Copyright 2002 OProfile authors
* @remark Read the file COPYING
*
* @author John Levon <levon@movementarian.org>
*/
#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/smp.h>
#include <linux/oprofile.h>
#include <linux/profile.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/hrtimer.h>
#include <asm/irq_regs.h>
#include <asm/ptrace.h>
#include "oprof.h"
static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
static int ctr_running;
static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
{
oprofile_add_sample(get_irq_regs(), 0);
hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
return HRTIMER_RESTART;
}
static void __oprofile_hrtimer_start(void *unused)
{
struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
if (!ctr_running)
return;
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = oprofile_hrtimer_notify;
hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
HRTIMER_MODE_REL_PINNED);
}
static int oprofile_hrtimer_start(void)
{
get_online_cpus();
ctr_running = 1;
on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
put_online_cpus();
return 0;
}
static void __oprofile_hrtimer_stop(int cpu)
{
struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
if (!ctr_running)
return;
hrtimer_cancel(hrtimer);
}
static void oprofile_hrtimer_stop(void)
{
int cpu;
get_online_cpus();
for_each_online_cpu(cpu)
__oprofile_hrtimer_stop(cpu);
ctr_running = 0;
put_online_cpus();
}
static int __cpuinit oprofile_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
long cpu = (long) hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
smp_call_function_single(cpu, __oprofile_hrtimer_start,
NULL, 1);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
__oprofile_hrtimer_stop(cpu);
break;
}
return NOTIFY_OK;
}
static struct notifier_block __refdata oprofile_cpu_notifier = {
.notifier_call = oprofile_cpu_notify,
};
static int oprofile_hrtimer_setup(void)
{
return register_hotcpu_notifier(&oprofile_cpu_notifier);
}
static void oprofile_hrtimer_shutdown(void)
{
unregister_hotcpu_notifier(&oprofile_cpu_notifier);
}
int oprofile_timer_init(struct oprofile_operations *ops)
{
ops->create_files = NULL;
ops->setup = oprofile_hrtimer_setup;
ops->shutdown = oprofile_hrtimer_shutdown;
ops->start = oprofile_hrtimer_start;
ops->stop = oprofile_hrtimer_stop;
ops->cpu_type = "timer";
printk(KERN_INFO "oprofile: using timer interrupt.\n");
return 0;
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...