Re: [PATCH 2/5] sched/vtime: get rid of generic vtime_task_switch() implementation

2024-02-06 Thread Frederic Weisbecker
Le Sun, Jan 28, 2024 at 08:58:51PM +0100, Alexander Gordeev a écrit :
> The generic vtime_task_switch() implementation gets built only
> if __ARCH_HAS_VTIME_TASK_SWITCH is not defined, but requires an
> architecture to implement arch_vtime_task_switch() callback at
> the same time, which is confusing.
> 
> Further, arch_vtime_task_switch() is implemented for 32-bit PowerPC
> architecture only and vtime_task_switch() generic variant is rather
> superfluous.
> 
> Simplify the whole vtime_task_switch() wiring by moving the existing
> generic implementation to PowerPC.
> 
> Signed-off-by: Alexander Gordeev 

Reviewed-by: Frederic Weisbecker 


[PATCH 2/5] sched/vtime: get rid of generic vtime_task_switch() implementation

2024-01-28 Thread Alexander Gordeev
The generic vtime_task_switch() implementation gets built only
if __ARCH_HAS_VTIME_TASK_SWITCH is not defined, but requires an
architecture to implement arch_vtime_task_switch() callback at
the same time, which is confusing.

Further, arch_vtime_task_switch() is implemented for 32-bit PowerPC
architecture only and vtime_task_switch() generic variant is rather
superfluous.

Simplify the whole vtime_task_switch() wiring by moving the existing
generic implementation to PowerPC.

Signed-off-by: Alexander Gordeev 
---
 arch/powerpc/include/asm/cputime.h | 13 -
 arch/powerpc/kernel/time.c | 22 ++
 kernel/sched/cputime.c | 13 -
 3 files changed, 22 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/include/asm/cputime.h 
b/arch/powerpc/include/asm/cputime.h
index 4961fb38e438..aff858ca99c0 100644
--- a/arch/powerpc/include/asm/cputime.h
+++ b/arch/powerpc/include/asm/cputime.h
@@ -32,23 +32,10 @@
 #ifdef CONFIG_PPC64
 #define get_accounting(tsk)(_paca()->accounting)
 #define raw_get_accounting(tsk)(_paca->accounting)
-static inline void arch_vtime_task_switch(struct task_struct *tsk) { }
 
 #else
 #define get_accounting(tsk)(_thread_info(tsk)->accounting)
 #define raw_get_accounting(tsk)get_accounting(tsk)
-/*
- * Called from the context switch with interrupts disabled, to charge all
- * accumulated times to the current process, and to prepare accounting on
- * the next process.
- */
-static inline void arch_vtime_task_switch(struct task_struct *prev)
-{
-   struct cpu_accounting_data *acct = get_accounting(current);
-   struct cpu_accounting_data *acct0 = get_accounting(prev);
-
-   acct->starttime = acct0->starttime;
-}
 #endif
 
 /*
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index df20cf201f74..c0fdc6d94fee 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -354,6 +354,28 @@ void vtime_flush(struct task_struct *tsk)
acct->hardirq_time = 0;
acct->softirq_time = 0;
 }
+
+/*
+ * Called from the context switch with interrupts disabled, to charge all
+ * accumulated times to the current process, and to prepare accounting on
+ * the next process.
+ */
+void vtime_task_switch(struct task_struct *prev)
+{
+   if (is_idle_task(prev))
+   vtime_account_idle(prev);
+   else
+   vtime_account_kernel(prev);
+
+   vtime_flush(prev);
+
+   if (!IS_ENABLED(CONFIG_PPC64)) {
+   struct cpu_accounting_data *acct = get_accounting(current);
+   struct cpu_accounting_data *acct0 = get_accounting(prev);
+
+   acct->starttime = acct0->starttime;
+   }
+}
 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
 
 void __no_kcsan __delay(unsigned long loops)
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index af7952f12e6c..aa48b2ec879d 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -424,19 +424,6 @@ static inline void irqtime_account_process_tick(struct 
task_struct *p, int user_
  */
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 
-# ifndef __ARCH_HAS_VTIME_TASK_SWITCH
-void vtime_task_switch(struct task_struct *prev)
-{
-   if (is_idle_task(prev))
-   vtime_account_idle(prev);
-   else
-   vtime_account_kernel(prev);
-
-   vtime_flush(prev);
-   arch_vtime_task_switch(prev);
-}
-# endif
-
 void vtime_account_irq(struct task_struct *tsk, unsigned int offset)
 {
unsigned int pc = irq_count() - offset;
-- 
2.40.1