linux-kernel - [PATCH 2/2] Revert "nohz: Fix idle ticks in cpu summary line of /proc/stat" (commit 7386cdbf2f57ea8cff3c9fde93f206e58b9fe13f).

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Date:	Thu,  3 Jan 2013 18:58:57 -0800
From:	Srivatsa Vaddagiri <vatsa@...eaurora.org>
To:	Russell King <linux@....linux.org.uk>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Stephen Boyd <sboyd@...eaurora.org>,
	linux-arm-kernel@...ts.infradead.org,
	Mike Frysinger <vapier@...too.org>,
	uclinux-dist-devel@...ckfin.uclinux.org,
	Ralf Baechle <ralf@...ux-mips.org>, linux-mips@...ux-mips.org,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	linuxppc-dev@...ts.ozlabs.org,
	Martin Schwidefsky <schwidefsky@...ibm.com>,
	linux-s390@...r.kernel.org, Paul Mundt <lethal@...ux-sh.org>,
	linux-sh@...r.kernel.org, "David S. Miller" <davem@...emloft.net>,
	sparclinux@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org, mhocko@...e.cz,
	srivatsa.bhat@...ux.vnet.ibm.com
Cc:	linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
	Srivatsa Vaddagiri <vatsa@...eaurora.org>
Subject: [PATCH 2/2] Revert "nohz: Fix idle ticks in cpu summary line of /proc/stat" (commit 7386cdbf2f57ea8cff3c9fde93f206e58b9fe13f).

With offline cpus no longer beeing seen in nohz mode (ts->idle_active=0), we
don't need the check for cpu_online() introduced in commit 7386cdbf. Offline
cpu's idle time as last recorded in its ts->idle_sleeptime will be reported
(thus excluding its offline time as part of idle time statistics).

Cc: mhocko@...e.cz
Cc: srivatsa.bhat@...ux.vnet.ibm.com
Signed-off-by: Srivatsa Vaddagiri <vatsa@...eaurora.org>
---
 fs/proc/stat.c |   14 ++++----------
 1 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index e296572..64c3b31 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -45,13 +45,10 @@ static cputime64_t get_iowait_time(int cpu)
 
 static u64 get_idle_time(int cpu)
 {
-	u64 idle, idle_time = -1ULL;
-
-	if (cpu_online(cpu))
-		idle_time = get_cpu_idle_time_us(cpu, NULL);
+	u64 idle, idle_time = get_cpu_idle_time_us(cpu, NULL);
 
 	if (idle_time == -1ULL)
-		/* !NO_HZ or cpu offline so we can rely on cpustat.idle */
+		/* !NO_HZ so we can rely on cpustat.idle */
 		idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
 	else
 		idle = usecs_to_cputime64(idle_time);
@@ -61,13 +58,10 @@ static u64 get_idle_time(int cpu)
 
 static u64 get_iowait_time(int cpu)
 {
-	u64 iowait, iowait_time = -1ULL;
-
-	if (cpu_online(cpu))
-		iowait_time = get_cpu_iowait_time_us(cpu, NULL);
+	u64 iowait, iowait_time = get_cpu_iowait_time_us(cpu, NULL);
 
 	if (iowait_time == -1ULL)
-		/* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
+		/* !NO_HZ so we can rely on cpustat.iowait */
 		iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
 	else
 		iowait = usecs_to_cputime64(iowait_time);
-- 
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