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Message-Id: <af8fe0a5bebd1745ceec07813fa55f1569930f2b.1533151550.git.christophe.leroy@c-s.fr>
Date: Thu, 2 Aug 2018 07:53:57 +0000 (UTC)
From: Christophe Leroy <christophe.leroy@....fr>
To: Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>
Cc: linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v5 1/3] powerpc/time: isolate scaled cputime accounting in
dedicated functions.
scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.
In preparation of the following patch that will remove
CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC32, this patch moves
all scaled cputing accounting logic into dedicated functions.
This patch doesn't change any functionality. It's only code
reorganisation.
Signed-off-by: Christophe Leroy <christophe.leroy@....fr>
---
v5:
- v4 patch split in two patches. First part isolates scaled cputime accounting
in dedicated functions, second part activates it only on PPC64.
- read_spurr() kept as a separate function.
v4:
- Using the correct symbol CONFIG_ARCH_HAS_SCALED_CPUTIME instead of ARCH_HAS_SCALED_CPUTIME
- Grouped CONFIG_ARCH_HAS_SCALED_CPUTIME related code in dedicated functions to reduce the number of #ifdefs
- Integrated read_spurr() directly into the related function.
v3: Rebased following modifications in xmon.c
v2: added ifdefs in xmon to fix compilation error
arch/powerpc/kernel/time.c | 69 +++++++++++++++++++++++++++++-----------------
1 file changed, 43 insertions(+), 26 deletions(-)
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 70f145e02487..6196bd7393a3 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -281,26 +281,16 @@ static inline u64 calculate_stolen_time(u64 stop_tb)
* Account time for a transition between system, hard irq
* or soft irq state.
*/
-static unsigned long vtime_delta(struct task_struct *tsk,
- unsigned long *stime_scaled,
- unsigned long *steal_time)
+static unsigned long vtime_delta_scaled(struct cpu_accounting_data *acct,
+ unsigned long now, unsigned long stime)
{
- unsigned long now, nowscaled, deltascaled;
- unsigned long stime;
+ unsigned long stime_scaled;
+ unsigned long nowscaled, deltascaled;
unsigned long utime, utime_scaled;
- struct cpu_accounting_data *acct = get_accounting(tsk);
- WARN_ON_ONCE(!irqs_disabled());
-
- now = mftb();
nowscaled = read_spurr(now);
- stime = now - acct->starttime;
- acct->starttime = now;
deltascaled = nowscaled - acct->startspurr;
acct->startspurr = nowscaled;
-
- *steal_time = calculate_stolen_time(now);
-
utime = acct->utime - acct->utime_sspurr;
acct->utime_sspurr = acct->utime;
@@ -314,18 +304,38 @@ static unsigned long vtime_delta(struct task_struct *tsk,
* the user ticks get saved up in paca->user_time_scaled to be
* used by account_process_tick.
*/
- *stime_scaled = stime;
+ stime_scaled = stime;
utime_scaled = utime;
if (deltascaled != stime + utime) {
if (utime) {
- *stime_scaled = deltascaled * stime / (stime + utime);
- utime_scaled = deltascaled - *stime_scaled;
+ stime_scaled = deltascaled * stime / (stime + utime);
+ utime_scaled = deltascaled - stime_scaled;
} else {
- *stime_scaled = deltascaled;
+ stime_scaled = deltascaled;
}
}
acct->utime_scaled += utime_scaled;
+ return stime_scaled;
+}
+
+static unsigned long vtime_delta(struct task_struct *tsk,
+ unsigned long *stime_scaled,
+ unsigned long *steal_time)
+{
+ unsigned long now, stime;
+ struct cpu_accounting_data *acct = get_accounting(tsk);
+
+ WARN_ON_ONCE(!irqs_disabled());
+
+ now = mftb();
+ stime = now - acct->starttime;
+ acct->starttime = now;
+
+ *stime_scaled = vtime_delta_scaled(acct, now, stime);
+
+ *steal_time = calculate_stolen_time(now);
+
return stime;
}
@@ -364,6 +374,19 @@ void vtime_account_idle(struct task_struct *tsk)
acct->idle_time += stime + steal_time;
}
+static void vtime_flush_scaled(struct task_struct *tsk,
+ struct cpu_accounting_data *acct)
+{
+ if (acct->utime_scaled)
+ tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
+ if (acct->stime_scaled)
+ tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
+
+ acct->utime_scaled = 0;
+ acct->utime_sspurr = 0;
+ acct->stime_scaled = 0;
+}
+
/*
* Account the whole cputime accumulated in the paca
* Must be called with interrupts disabled.
@@ -378,9 +401,6 @@ void vtime_flush(struct task_struct *tsk)
if (acct->utime)
account_user_time(tsk, cputime_to_nsecs(acct->utime));
- if (acct->utime_scaled)
- tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
-
if (acct->gtime)
account_guest_time(tsk, cputime_to_nsecs(acct->gtime));
@@ -393,8 +413,6 @@ void vtime_flush(struct task_struct *tsk)
if (acct->stime)
account_system_index_time(tsk, cputime_to_nsecs(acct->stime),
CPUTIME_SYSTEM);
- if (acct->stime_scaled)
- tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
if (acct->hardirq_time)
account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),
@@ -403,14 +421,13 @@ void vtime_flush(struct task_struct *tsk)
account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),
CPUTIME_SOFTIRQ);
+ vtime_flush_scaled(tsk, acct);
+
acct->utime = 0;
- acct->utime_scaled = 0;
- acct->utime_sspurr = 0;
acct->gtime = 0;
acct->steal_time = 0;
acct->idle_time = 0;
acct->stime = 0;
- acct->stime_scaled = 0;
acct->hardirq_time = 0;
acct->softirq_time = 0;
}
--
2.13.3
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