[PATCH] powerpc 32: Provides VIRT_CPU_ACCOUNTING

From: Christophe Leroy
Date: Wed Mar 19 2014 - 18:32:07 EST

Next message: Mathieu Desnoyers: "[RFC PATCH v6 2/3] Tracepoint API doc update: data argument"
Previous message: Mathieu Desnoyers: "[RFC PATCH v6 3/3] Tracepoint: register/unregister struct tracepoint"
Next in thread: Scott Wood: "Re: [PATCH] powerpc 32: Provides VIRT_CPU_ACCOUNTING"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture.
Unlike PPC64, PPC32 doesn't provide the PACA register. Therefore the
implementation is similar to the one done in the IA64 architecture.
It is based on additional information added to the Task Info structure.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>

Index: b/arch/powerpc/Kconfig
===================================================================
--- b/arch/powerpc/Kconfig (revision 5607)
+++ b/arch/powerpc/Kconfig (revision 5608)
@@ -138,6 +138,7 @@
select OLD_SIGSUSPEND
select OLD_SIGACTION if PPC32
select HAVE_DEBUG_STACKOVERFLOW
+ select HAVE_VIRT_CPU_ACCOUNTING

config EARLY_PRINTK
bool
Index: b/arch/powerpc/kernel/time.c
===================================================================
--- b/arch/powerpc/kernel/time.c (revision 5607)
+++ b/arch/powerpc/kernel/time.c (revision 5608)
@@ -162,7 +162,9 @@

cputime_t cputime_one_jiffy;

+#ifdef CONFIG_PPC_SPLPAR
void (*dtl_consumer)(struct dtl_entry *, u64);
+#endif

static void calc_cputime_factors(void)
{
@@ -178,6 +180,7 @@
__cputime_clockt_factor = res.result_low;
}

+#ifdef CONFIG_PPC64
/*
* Read the SPURR on systems that have it, otherwise the PURR,
* or if that doesn't exist return the timebase value passed in.
@@ -190,6 +193,7 @@
return mfspr(SPRN_PURR);
return tb;
}
+#endif

#ifdef CONFIG_PPC_SPLPAR

@@ -291,6 +295,7 @@
* Account time for a transition between system, hard irq
* or soft irq state.
*/
+#ifdef CONFIG_PPC64
static u64 vtime_delta(struct task_struct *tsk,
u64 *sys_scaled, u64 *stolen)
{
@@ -377,7 +382,70 @@
get_paca()->utime_sspurr = 0;
account_user_time(tsk, utime, utimescaled);
}
+#else

+void vtime_account_user(struct task_struct *tsk)
+{
+ cputime_t delta_utime;
+ struct thread_info *ti = task_thread_info(tsk);
+
+ if (ti->ac_utime) {
+ delta_utime = ti->ac_utime;
+ account_user_time(tsk, delta_utime, delta_utime);
+ ti->ac_utime = 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 arch_vtime_task_switch(struct task_struct *prev)
+{
+ struct thread_info *pi = task_thread_info(prev);
+ struct thread_info *ni = task_thread_info(current);
+
+ ni->ac_stamp = pi->ac_stamp;
+ ni->ac_stime = ni->ac_utime = 0;
+}
+
+/*
+ * Account time for a transition between system, hard irq or soft irq state.
+ * Note that this function is called with interrupts enabled.
+ */
+static cputime_t vtime_delta(struct task_struct *tsk)
+{
+ struct thread_info *ti = task_thread_info(tsk);
+ __u32 delta_stime;
+ __u32 now;
+
+ WARN_ON_ONCE(!irqs_disabled());
+
+ now = mftbl();
+
+ delta_stime = ti->ac_stime + (now - ti->ac_stamp);
+ ti->ac_stime = 0;
+ ti->ac_stamp = now;
+
+ return (cputime_t)delta_stime;
+}
+
+void vtime_account_system(struct task_struct *tsk)
+{
+ cputime_t delta = vtime_delta(tsk);
+
+ account_system_time(tsk, 0, delta, delta);
+}
+EXPORT_SYMBOL_GPL(vtime_account_system);
+
+void vtime_account_idle(struct task_struct *tsk)
+{
+ account_idle_time(vtime_delta(tsk));
+}
+
+#endif
+
#else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#define calc_cputime_factors()
#endif
@@ -871,6 +939,8 @@
ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
}

+ mttbl(0);
+ mttbu(0);
tb_ticks_per_jiffy = ppc_tb_freq / HZ;
tb_ticks_per_sec = ppc_tb_freq;
tb_ticks_per_usec = ppc_tb_freq / 1000000;
Index: b/arch/powerpc/kernel/entry_32.S
===================================================================
--- b/arch/powerpc/kernel/entry_32.S (revision 5607)
+++ b/arch/powerpc/kernel/entry_32.S (revision 5608)
@@ -177,6 +177,12 @@
addi r12,r12,-1
stw r12,4(r11)
#endif
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ CURRENT_THREAD_INFO(r9, r1)
+ tophys(r9, r9)
+ ACCOUNT_CPU_USER_ENTRY(r9, r11, r12)
+#endif
+
b 3f

2: /* if from kernel, check interrupted DOZE/NAP mode and
@@ -406,6 +412,13 @@
lwarx r7,0,r1
END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
stwcx. r0,0,r1 /* to clear the reservation */
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ andi. r4,r8,MSR_PR
+ beq 3f
+ CURRENT_THREAD_INFO(r4, r1)
+ ACCOUNT_CPU_USER_EXIT(r4, r5, r7)
+3:
+#endif
lwz r4,_LINK(r1)
lwz r5,_CCR(r1)
mtlr r4
@@ -841,6 +854,10 @@
andis. r10,r0,DBCR0_IDM@h
bnel- load_dbcr0
#endif
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ CURRENT_THREAD_INFO(r9, r1)
+ ACCOUNT_CPU_USER_EXIT(r9, r10, r11)
+#endif

b restore

Index: b/arch/powerpc/kernel/asm-offsets.c
===================================================================
--- b/arch/powerpc/kernel/asm-offsets.c (revision 5607)
+++ b/arch/powerpc/kernel/asm-offsets.c (revision 5608)
@@ -167,6 +167,10 @@
DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
DEFINE(TI_TASK, offsetof(struct thread_info, task));
DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
+ DEFINE(TI_AC_STAMP, offsetof(struct thread_info, ac_stamp));
+ DEFINE(TI_AC_LEAVE, offsetof(struct thread_info, ac_leave));
+ DEFINE(TI_AC_STIME, offsetof(struct thread_info, ac_stime));
+ DEFINE(TI_AC_UTIME, offsetof(struct thread_info, ac_utime));

#ifdef CONFIG_PPC64
DEFINE(DCACHEL1LINESIZE, offsetof(struct ppc64_caches, dline_size));
Index: b/arch/powerpc/include/asm/thread_info.h
===================================================================
--- b/arch/powerpc/include/asm/thread_info.h (revision 5607)
+++ b/arch/powerpc/include/asm/thread_info.h (revision 5608)
@@ -43,6 +43,12 @@
int cpu; /* cpu we're on */
int preempt_count; /* 0 => preemptable,
<0 => BUG */
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ __u32 ac_stamp;
+ __u32 ac_leave;
+ __u32 ac_stime;
+ __u32 ac_utime;
+#endif
struct restart_block restart_block;
unsigned long local_flags; /* private flags for thread */

@@ -58,6 +64,8 @@
.task = &tsk, \
.exec_domain = &default_exec_domain, \
.cpu = 0, \
+ .ac_stime = 0, \
+ .ac_utime = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
.restart_block = { \
.fn = do_no_restart_syscall, \
Index: b/arch/powerpc/include/asm/cputime.h
===================================================================
--- b/arch/powerpc/include/asm/cputime.h (revision 5607)
+++ b/arch/powerpc/include/asm/cputime.h (revision 5608)
@@ -228,7 +228,11 @@

#define cputime64_to_clock_t(ct) cputime_to_clock_t((cputime_t)(ct))

+#ifdef CONFIG_PPC64
static inline void arch_vtime_task_switch(struct task_struct *tsk) { }
+#else
+extern void arch_vtime_task_switch(struct task_struct *tsk);
+#endif

#endif /* __KERNEL__ */
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
Index: b/arch/powerpc/include/asm/ppc_asm.h
===================================================================
--- b/arch/powerpc/include/asm/ppc_asm.h (revision 5607)
+++ b/arch/powerpc/include/asm/ppc_asm.h (revision 5608)
@@ -25,10 +25,16 @@
*/

#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+#ifdef CONFIG_PPC64
#define ACCOUNT_CPU_USER_ENTRY(ra, rb)
#define ACCOUNT_CPU_USER_EXIT(ra, rb)
+#else /* CONFIG_PPC64 */
+#define ACCOUNT_CPU_USER_ENTRY(ti, ra, rb)
+#define ACCOUNT_CPU_USER_EXIT(ti, ra, rb)
+#endif
#define ACCOUNT_STOLEN_TIME
-#else
+#else /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
+#ifdef CONFIG_PPC64
#define ACCOUNT_CPU_USER_ENTRY(ra, rb) \
MFTB(ra); /* get timebase */ \
ld rb,PACA_STARTTIME_USER(r13); \
@@ -68,7 +74,27 @@
#define ACCOUNT_STOLEN_TIME

#endif /* CONFIG_PPC_SPLPAR */
+#else /* CONFIG_PPC64 */
+#define ACCOUNT_CPU_USER_ENTRY(ti, ra, rb) \
+ MFTB(ra); \
+ lwz rb, TI_AC_LEAVE(ti); \
+ stw ra, TI_AC_STAMP(ti); /* AC_STAMP = NOW */ \
+ subf rb, rb, ra; /* R = NOW - AC_LEAVE */ \
+ lwz ra, TI_AC_UTIME(ti); \
+ add ra, rb, ra; /* AC_UTIME += R */ \
+ stw ra, TI_AC_UTIME(ti); \

+#define ACCOUNT_CPU_USER_EXIT(ti, ra, rb) \
+ MFTB(ra); \
+ lwz rb, TI_AC_STAMP(ti); \
+ stw ra, TI_AC_LEAVE(ti); \
+ subf rb, rb, ra; /* R = NOW - AC_STAMP */ \
+ lwz ra, TI_AC_STIME(ti); \
+ add ra, rb, ra; /* AC_STIME += R */ \
+ stw ra, TI_AC_STIME(ti); \
+
+#endif
+
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */

/*
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: Mathieu Desnoyers: "[RFC PATCH v6 2/3] Tracepoint API doc update: data argument"
Previous message: Mathieu Desnoyers: "[RFC PATCH v6 3/3] Tracepoint: register/unregister struct tracepoint"
Next in thread: Scott Wood: "Re: [PATCH] powerpc 32: Provides VIRT_CPU_ACCOUNTING"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]