The commit fa13a5a1f25f671d084d8884be96fc48d9b68275, unconditionally calls
update_process_tick() in system context. In the deterministic accounting case
this is the correct thing to do. However, in the non-deterministic accounting
case we need to not do this, and results in the time accounted as
hardware irq time being artificially elevated.
Also this patch collapses 2 consecutive '#ifdef CONFIG_VIRT_CPU_ACCOUNTING'
checks in time.h into for neatness.
Signed-off-by: Tony Breeds <[EMAIL PROTECTED]>
---
The problem was seen and reported by Johannes Berg and Frederik Himpe.
Paul, I think this is good for 2.6.24.
arch/powerpc/kernel/process.c | 2 +-
include/asm-powerpc/time.h | 12 ++++--------
2 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 41e13f4..b9d8837 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -350,7 +350,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
local_irq_save(flags);
account_system_vtime(current);
- account_process_tick(current, 0);
+ account_process_vtime(current);
calculate_steal_time();
last = _switch(old_thread, new_thread);
diff --git a/include/asm-powerpc/time.h b/include/asm-powerpc/time.h
index 780f826..8a2c8db 100644
--- a/include/asm-powerpc/time.h
+++ b/include/asm-powerpc/time.h
@@ -237,18 +237,14 @@ struct cpu_usage {
DECLARE_PER_CPU(struct cpu_usage, cpu_usage_array);
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-extern void account_process_vtime(struct task_struct *tsk);
-#else
-#define account_process_vtime(tsk) do { } while (0)
-#endif
-
#if defined(CONFIG_VIRT_CPU_ACCOUNTING)
extern void calculate_steal_time(void);
extern void snapshot_timebases(void);
+#define account_process_vtime(tsk) account_process_tick(current, 0);
#else
-#define calculate_steal_time() do { } while (0)
-#define snapshot_timebases() do { } while (0)
+#define calculate_steal_time() do { } while (0)
+#define snapshot_timebases() do { } while (0)
+#define account_process_vtime(tsk) do { } while (0)
#endif
extern void secondary_cpu_time_init(void);
--
1.5.3.6
Yours Tony
linux.conf.au http://linux.conf.au/ || http://lca2008.linux.org.au/
Jan 28 - Feb 02 2008 The Australian Linux Technical Conference!
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