[RFC PATCH 05/11] time,nohz: add cpu parameter to account_steal_time

[riel@redhat.com]

From: Rik van Riel <riel@redhat.com>

Simple transformation to allow tick based sampling from a remote
cpu. Additional changes may be needed to actually acquire the
steal time info for remote cpus from the host/hypervisor.

Signed-off-by: Rik van Riel <riel@redhat.com>
---
 include/linux/kernel_stat.h | 2 +-
 kernel/sched/cputime.c      | 9 +++++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index 25a822f6f000..4490aef2f149 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -80,7 +80,7 @@ static inline unsigned int kstat_cpu_irqs_sum(unsigned int cpu)
 
 extern void account_user_time(struct task_struct *, cputime_t, cputime_t);
 extern void account_system_time(struct task_struct *, int, cputime_t, cputime_t);
-extern void account_steal_time(cputime_t);
+extern void account_steal_time(int cpu, cputime_t);
 extern void account_idle_time(cputime_t);
 
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 9717d86cf2ab..b684c48ad954 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -232,9 +232,10 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
  * Account for involuntary wait time.
  * @cputime: the cpu time spent in involuntary wait
  */
-void account_steal_time(cputime_t cputime)
+void account_steal_time(int cpu, cputime_t cputime)
 {
-	u64 *cpustat = kcpustat_this_cpu->cpustat;
+	struct kernel_cpustat *kstat = &kcpustat_cpu(cpu);
+	u64 *cpustat = kstat->cpustat;
 
 	cpustat[CPUTIME_STEAL] += (__force u64) cputime;
 }
@@ -272,7 +273,7 @@ static __always_inline bool steal_account_process_tick(int cpu)
 		steal_ct = nsecs_to_cputime(steal);
 		cpu_rq(cpu)->prev_steal_time += cputime_to_nsecs(steal_ct);
 
-		account_steal_time(steal_ct);
+		account_steal_time(cpu, steal_ct);
 		return steal_ct;
 	}
 #endif
@@ -502,7 +503,7 @@ void account_process_tick(struct task_struct *p, int user_tick)
  */
 void account_steal_ticks(unsigned long ticks)
 {
-	account_steal_time(jiffies_to_cputime(ticks));
+	account_steal_time(smp_processor_id(), jiffies_to_cputime(ticks));
 }
 
 /*
-- 
2.1.0