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

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Submitter Srivatsa Vaddagiri
Date Jan. 4, 2013, 2:58 a.m.
Message ID <1357268337-8025-1-git-send-email-vatsa@codeaurora.org>
Download mbox | patch
Permalink /patch/209365/
State Not Applicable
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Comments

Srivatsa Vaddagiri - Jan. 4, 2013, 2:58 a.m.
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@suse.cz
Cc: srivatsa.bhat@linux.vnet.ibm.com
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
---
 fs/proc/stat.c |   14 ++++----------
 1 files changed, 4 insertions(+), 10 deletions(-)
Sergei Shtylyov - Jan. 4, 2013, 12:13 p.m.
Hello.

On 04-01-2013 6:58, Srivatsa Vaddagiri wrote:

> 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

    Please also specify the summary of that commit in parens (or however you 
like).

> 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@suse.cz
> Cc: srivatsa.bhat@linux.vnet.ibm.com
> Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>

WBR, Sergei
Srivatsa Vaddagiri - Jan. 4, 2013, 7:29 p.m.
* Sergei Shtylyov <sshtylyov@mvista.com> [2013-01-04 16:13:42]:

> >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
> 
>    Please also specify the summary of that commit in parens (or
> however you like).

I had that in Subject line, but yes would be good to include in commit message
as well. I will incorporate that change alongwith anything else required in
next version of this patch.

- vatsa
Sergei Shtylyov - Jan. 4, 2013, 8:42 p.m.
Hello.

On 01/04/2013 10:29 PM, Srivatsa Vaddagiri wrote:

>>> 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

>>    Please also specify the summary of that commit in parens (or
>> however you like).

> I had that in Subject line, but yes would be good to include in commit message
> as well. I will incorporate that change alongwith anything else required in
> next version of this patch.

   Ah, that was a revert with atypical subject -- didn't notice. Then there's no
need to specify it twice.

> - vatsa

WBR, Sergei

Patch

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);