Bug 695283 - function_graph is not listed in /sys/kernel/debug/tracing/available_tracers, but /boot/config shows it as enabled
Summary: function_graph is not listed in /sys/kernel/debug/tracing/available_tracers, ...
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 14
Hardware: i686
OS: Linux
unspecified
low
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-04-11 10:22 UTC by Robin Green
Modified: 2011-04-12 15:54 UTC (History)
6 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2011-04-12 15:54:00 UTC
Type: ---
Embargoed:

Attachments (Terms of Use)

Description Robin Green 2011-04-11 10:22:00 UTC 
Description of problem:
According to /boot/config-2.6.35.11-83.fc14.i686.PAE, function_graph tracing is configured:

CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y

but it doesn't show up in /sys/kernel/debug/tracing/available_tracers

Version-Release number of selected component (if applicable):
kernel-PAE-2.6.35.11-83.fc14.i686

How reproducible:
Haven't tried

Steps to Reproduce:
1. Mount debugfs at /sys/kernel/debug
2. cat /sys/kernel/debug/tracing/available_tracers
  
Actual results:
ksym_tracer blk kmemtrace wakeup_rt wakeup function sysprof sched_switch nop

Expected results:
A list that includes function_graph

Additional info:
This problem was reported last year by someone else on LKML with a self-built kernel, but there were no replies on-list.
Comment 1 Robin Green 2011-04-12 15:54:00 UTC 
It's not supported on x86 unless CC_OPTIMIZE_FOR_SIZE is disabled, which is enabled in the Fedora kernel.
Note You need to log in before you can comment on or make changes to this bug.