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From: Shuah Khan <shuahkh@osg.samsung.com>
To: rostedt@goodmis.org, mingo@redhat.com, gregkh@linuxfoundation.org
Cc: Shuah Khan <shuahkh@osg.samsung.com>, linux-kernel@vger.kernel.org
Subject: [PATCH 0/3] kobject tracepoints
Date: Tue,  6 Sep 2016 11:49:22 -0600
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Add kobject trace points to track kobject operations: init, add, set_name,
init_and_add, create_and_add, move, rename, get, put, cleanup, and del.

Kobject trace points can aid in debugging, generating status and graphs
on kobjects in the kernel and their hierarchy.

This patch series adds kobject tracepoints and adds calls to tracepoints
from kobject init, add, set_name, init_and_add, create_and_add, move,
rename, get, put, cleanup, and del operations.

A suggestion to provide more visibility into kboject lifetimes came out of
a discussion at my Embedded data structure lifetime talk at LinuxCon NA in
Toronto. As I thought about on how to provide visibility, I decided adding
traces provides a boot and run-time facility to trace kobject operations
without needing compile special kernels and also without impacting run-time
unless trace is enabled. Hence, this resulting patch series.

Example traces:

<...>-13632 [003] d... 11296.965114: kobject_get: KOBJECT: 1:0:0:0 (f
fff88034aeb1348) state=1 parent= target1:0:0 (ffff88038c875db8) counter= 19
           <...>-13632 [003] d... 11296.965167: kobject_get: KOBJECT: 1:0:0:0 (ffff88034aeb1348) state=1 parent= target1:0:0 (ffff88038c875db8) counter= 20
           <...>-13632 [003] d... 11296.965218: kobject_get: KOBJECT: 1:0:0:0 (ffff88034aeb1348) state=1 parent= target1:0:0 (ffff88038c875db8) counter= 21
           <...>-13632 [003] d... 11296.965269: kobject_get: KOBJECT: 1:0:0:0 (ffff88034aeb1348) state=1 parent= target1:0:0 (ffff88038c875db8) counter= 22
          <idle>-0     [006] ..s. 11296.965378: kobject_put: KOBJECT: 1:0:0:0 (ffff88034aeb1348) state=1 parent= target1:0:0 (ffff88038c875db8) counter= 21
          <idle>-0     [006] .Ns. 11296.965542: kobject_put: KOBJECT: 1:0:0:0 (ffff88034aeb1348) state=1 parent= target1:0:0 (ffff88038c875db8) counter= 20
     ksoftirqd/6-46    [006] ..s. 11296.965633: kobject_put: KOBJECT: 1:0:0:0 (ffff88034aeb1348) state=1 parent= target1:0:0 (ffff88038c875db8) counter= 19
     ksoftirqd/6-46    [006] ..s. 11296.965703: kobject_put: KOBJECT: 1:0:0:0 (ffff88034aeb1348) state=1 parent= target1:0:0 (ffff88038c875db8) counter= 18

Shuah Khan (3):
  kobject: add kobject trace points
  kobject: add kobject trace prototypes
  kobject: Add calls to kobject trace points

 include/trace/events/kobject.h | 259 +++++++++++++++++++++++++++++++++++++++++
 lib/Makefile                   |   2 +-
 lib/kobject.c                  |  22 ++++
 lib/kobject_traces.c           |  32 +++++
 4 files changed, 314 insertions(+), 1 deletion(-)
 create mode 100644 include/trace/events/kobject.h
 create mode 100644 lib/kobject_traces.c

-- 
2.7.4