[patch] timer_stats, doc: Readout of /proc/timer_stats doesn't disable sampling

[patch] timer_stats, doc: Readout of /proc/timer_stats doesn't disable sampling

[Michael Kerrisk (man-pages)]

From: Michael Kerrisk <mtk.manpages@gmail.com>

Some simple testing shows that reading from /proc/timer_stats
does not disable sampling. Looking back over past source code,
it appears that it never did.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
---
 Documentation/timers/timer_stats.txt | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/timers/timer_stats.txt b/Documentation/timers/timer_stats.txt
index 8abd40b..de835ee 100644
--- a/Documentation/timers/timer_stats.txt
+++ b/Documentation/timers/timer_stats.txt
@@ -39,9 +39,9 @@ To stop a sample period issue:
 The statistics can be retrieved by:
 # cat /proc/timer_stats
 
-The readout of /proc/timer_stats automatically disables sampling. The sampled
-information is kept until a new sample period is started. This allows multiple
-readouts.
+While sampling is enabled, each readout from /proc/timer_stats will see
+newly updated statistics. Once sampling is disabled, the sampled information
+is kept until a new sample period is started. This allows multiple readouts.
 
 Sample output of /proc/timer_stats:
 
-- 
1.9.0

[tip:timers/core] timer_stats/doc: Fix /proc/ timer_stats documentation

[tip-bot for Michael Kerrisk]

Commit-ID:  2779ac167b1a1bf8153dca9f3a141c6148c6b89f
Gitweb:     http://git.kernel.org/tip/2779ac167b1a1bf8153dca9f3a141c6148c6b89f
Author:     Michael Kerrisk <mtk.manpages@gmail.com>
AuthorDate: Fri, 2 May 2014 12:13:10 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 4 May 2014 20:46:32 +0200

timer_stats/doc: Fix /proc/timer_stats documentation

Documentation/timers/timer_stats.txt claims:

 "The readout of /proc/timer_stats automatically disables sampling. The sampled
  information is kept until a new sample period is started. This allows multiple
  readouts."

Some simple testing shows that reading from /proc/timer_stats
does not disable sampling. Looking back over past source code,
it appears that it never did.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: http://lkml.kernel.org/r/53636FB6.9060407@gmail.com
[ Small tidyup of the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 Documentation/timers/timer_stats.txt | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/timers/timer_stats.txt b/Documentation/timers/timer_stats.txt
index 8abd40b..de835ee 100644
--- a/Documentation/timers/timer_stats.txt
+++ b/Documentation/timers/timer_stats.txt
@@ -39,9 +39,9 @@ To stop a sample period issue:
 The statistics can be retrieved by:
 # cat /proc/timer_stats
 
-The readout of /proc/timer_stats automatically disables sampling. The sampled
-information is kept until a new sample period is started. This allows multiple
-readouts.
+While sampling is enabled, each readout from /proc/timer_stats will see
+newly updated statistics. Once sampling is disabled, the sampled information
+is kept until a new sample period is started. This allows multiple readouts.
 
 Sample output of /proc/timer_stats:
 

[patch] timer_stats, doc: Readout of /proc/timer_stats doesn't disable sampling

[Michael Kerrisk (man-pages)]

From: Michael Kerrisk <mtk.manpages@gmail.com>

Some simple testing shows that reading from /proc/timer_stats
does not disable sampling. Looking back over past source code,
it appears that it never did.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/

Re: [patch] timer_stats, doc: Readout of /proc/timer_stats doesn't disable sampling

[Michael Kerrisk]

Sorry -- fatfingered in Thunderbird. Proper patch on its way shortly.

On Fri, May 2, 2014 at 11:29 AM, Michael Kerrisk (man-pages)
<mtk.manpages@gmail.com> wrote:
> From: Michael Kerrisk <mtk.manpages@gmail.com>
>
> Some simple testing shows that reading from /proc/timer_stats
> does not disable sampling. Looking back over past source code,
> it appears that it never did.
>
> Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
>
>
> --
> Michael Kerrisk
> Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
> Linux/UNIX System Programming Training: http://man7.org/training/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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-- 
Michael Kerrisk Linux man-pages maintainer;
http://www.kernel.org/doc/man-pages/
Author of "The Linux Programming Interface", http://blog.man7.org/