linux-kernel - [PATCH v4 2/2] powerpc/time: no steal_time when CONFIG_PPC

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Date:   Wed,  6 Jun 2018 14:21:10 +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>,
        Frederic Weisbecker <fweisbec@...il.com>,
        Nicholas Piggin <npiggin@...il.com>
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v4 2/2] powerpc/time: no steal_time when CONFIG_PPC_SPLPAR is
 not selected

If CONFIG_PPC_SPLPAR is not selected, steal_time will always
be NUL, so accounting it is pointless

Signed-off-by: Christophe Leroy <christophe.leroy@....fr>
---
 v4: removed the check in vtime_account_system(), the compiler removes the code regardless.
 v3: new

 arch/powerpc/kernel/time.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 7a9f4e2f22c8..eda78b1ed7d3 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -412,9 +412,6 @@ void vtime_flush(struct task_struct *tsk)
 	if (acct->gtime)
 		account_guest_time(tsk, cputime_to_nsecs(acct->gtime));
 
-	if (acct->steal_time)
-		account_steal_time(cputime_to_nsecs(acct->steal_time));
-
 	if (acct->idle_time)
 		account_idle_time(cputime_to_nsecs(acct->idle_time));
 
@@ -431,13 +428,17 @@ void vtime_flush(struct task_struct *tsk)
 
 	acct->utime = 0;
 	acct->gtime = 0;
-	acct->steal_time = 0;
 	acct->idle_time = 0;
 	acct->stime = 0;
 	acct->hardirq_time = 0;
 	acct->softirq_time = 0;
 
 	vtime_flush_scaled(tsk, acct);
+
+	if (IS_ENABLED(CONFIG_PPC_SPLPAR) && acct->steal_time) {
+		account_steal_time(cputime_to_nsecs(acct->steal_time));
+		acct->steal_time = 0;
+	}
 }
 
 #else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
-- 
2.13.3