taskstats scaled time cleanup
This moves the ability to scale cputime into generic code. This allows us
to fix the issue in kernel/timer.c (noticed by Balbir) where we could only
add an unscaled value to the scaled utime/stime.
This adds a cputime_to_scaled function. As before, the POWERPC version
does the scaling based on the last SPURR/PURR ratio calculated. The
generic and s390 (only other arch to implement asm/cputime.h) versions are
both NOPs.
Also moves the SPURR and PURR snapshots closer.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 5cd3db5..3b26fbd6 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -66,6 +66,7 @@
#include <asm/smp.h>
#include <asm/vdso_datapage.h>
#include <asm/firmware.h>
+#include <asm/cputime.h>
#ifdef CONFIG_PPC_ISERIES
#include <asm/iseries/it_lp_queue.h>
#include <asm/iseries/hv_call_xm.h>
@@ -189,6 +190,8 @@
EXPORT_SYMBOL(__cputime_sec_factor);
u64 __cputime_clockt_factor;
EXPORT_SYMBOL(__cputime_clockt_factor);
+DEFINE_PER_CPU(unsigned long, cputime_last_delta);
+DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta);
static void calc_cputime_factors(void)
{
@@ -257,8 +260,8 @@
}
account_system_time(tsk, 0, delta);
account_system_time_scaled(tsk, deltascaled);
- get_paca()->purrdelta = delta;
- get_paca()->spurrdelta = deltascaled;
+ per_cpu(cputime_last_delta, smp_processor_id()) = delta;
+ per_cpu(cputime_scaled_last_delta, smp_processor_id()) = deltascaled;
local_irq_restore(flags);
}
@@ -276,10 +279,7 @@
get_paca()->user_time = 0;
account_user_time(tsk, utime);
- /* Estimate the scaled utime by scaling the real utime based
- * on the last spurr to purr ratio */
- utimescaled = utime * get_paca()->spurrdelta / get_paca()->purrdelta;
- get_paca()->spurrdelta = get_paca()->purrdelta = 0;
+ utimescaled = cputime_to_scaled(utime);
account_user_time_scaled(tsk, utimescaled);
}
diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h
index 09204e4..1c1fa42 100644
--- a/include/asm-generic/cputime.h
+++ b/include/asm-generic/cputime.h
@@ -18,6 +18,7 @@
#define cputime_lt(__a, __b) ((__a) < (__b))
#define cputime_le(__a, __b) ((__a) <= (__b))
#define cputime_to_jiffies(__ct) (__ct)
+#define cputime_to_scaled(__ct) (__ct)
#define jiffies_to_cputime(__hz) (__hz)
typedef u64 cputime64_t;
diff --git a/include/asm-powerpc/cputime.h b/include/asm-powerpc/cputime.h
index 3108044..f42e623 100644
--- a/include/asm-powerpc/cputime.h
+++ b/include/asm-powerpc/cputime.h
@@ -52,12 +52,26 @@
* Convert cputime <-> jiffies
*/
extern u64 __cputime_jiffies_factor;
+DECLARE_PER_CPU(unsigned long, cputime_last_delta);
+DECLARE_PER_CPU(unsigned long, cputime_scaled_last_delta);
static inline unsigned long cputime_to_jiffies(const cputime_t ct)
{
return mulhdu(ct, __cputime_jiffies_factor);
}
+/* Estimate the scaled cputime by scaling the real cputime based on
+ * the last scaled to real ratio */
+static inline cputime_t cputime_to_scaled(const cputime_t ct)
+{
+ if (cpu_has_feature(CPU_FTR_SPURR) &&
+ per_cpu(cputime_last_delta, smp_processor_id()))
+ return ct *
+ per_cpu(cputime_scaled_last_delta, smp_processor_id())/
+ per_cpu(cputime_last_delta, smp_processor_id());
+ return ct;
+}
+
static inline cputime_t jiffies_to_cputime(const unsigned long jif)
{
cputime_t ct;
diff --git a/include/asm-powerpc/paca.h b/include/asm-powerpc/paca.h
index f6dfce0..748b35a 100644
--- a/include/asm-powerpc/paca.h
+++ b/include/asm-powerpc/paca.h
@@ -115,8 +115,6 @@
u64 system_time; /* accumulated system TB ticks */
u64 startpurr; /* PURR/TB value snapshot */
u64 startspurr; /* SPURR value snapshot */
- u64 purrdelta; /* FIXME: document */
- u64 spurrdelta; /* FIXME: document */
};
extern struct paca_struct paca[];
diff --git a/include/asm-s390/cputime.h b/include/asm-s390/cputime.h
index 4b3ef7c..133ce05 100644
--- a/include/asm-s390/cputime.h
+++ b/include/asm-s390/cputime.h
@@ -54,6 +54,7 @@
#define cputime_lt(__a, __b) ((__a) < (__b))
#define cputime_le(__a, __b) ((__a) <= (__b))
#define cputime_to_jiffies(__ct) (__div((__ct), 1000000 / HZ))
+#define cputime_to_scaled(__ct) (__ct)
#define jiffies_to_cputime(__hz) ((cputime_t)(__hz) * (1000000 / HZ))
#define cputime64_zero (0ULL)
diff --git a/kernel/timer.c b/kernel/timer.c
index 9fbb472..70b29b5 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -818,12 +818,14 @@
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
void account_process_tick(struct task_struct *p, int user_tick)
{
+ cputime_t one_jiffy = jiffies_to_cputime(1);
+
if (user_tick) {
- account_user_time(p, jiffies_to_cputime(1));
- account_user_time_scaled(p, jiffies_to_cputime(1));
+ account_user_time(p, one_jiffy);
+ account_user_time_scaled(p, cputime_to_scaled(one_jiffy));
} else {
- account_system_time(p, HARDIRQ_OFFSET, jiffies_to_cputime(1));
- account_system_time_scaled(p, jiffies_to_cputime(1));
+ account_system_time(p, HARDIRQ_OFFSET, one_jiffy);
+ account_system_time_scaled(p, cputime_to_scaled(one_jiffy));
}
}
#endif