Bug 716559 - RT Tuning Guide update
Summary: RT Tuning Guide update
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise MRG
Classification: Red Hat
Component: Realtime_Tuning_Guide
Version: 2.0
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: 2.1
: ---
Assignee: Alison Young
QA Contact: Jeff Needle
URL:
Whiteboard:
Depends On: 733203
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-06-24 21:18 UTC by Beth Uptagrafft
Modified: 2012-01-26 19:30 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-01-26 19:30:51 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)
ftrace documentation (78.02 KB, text/plain)
2011-06-24 21:18 UTC, Beth Uptagrafft
no flags Details
Event Tracing Documentation (9.24 KB, text/plain)
2011-06-24 21:19 UTC, Beth Uptagrafft
no flags Details

Description Beth Uptagrafft 2011-06-24 21:18:06 UTC
Created attachment 509846 [details]
ftrace documentation

ftrace.txt and events.txt are new docs that Steven updated for MRG Documentation/trace/*.  RT Engineering needs to determine what to fold into our Tuning Guide.

Comment 1 Beth Uptagrafft 2011-06-24 21:19:28 UTC
Created attachment 509847 [details]
Event Tracing Documentation

Comment 2 Alison Young 2011-08-23 01:42:26 UTC
Hi Beth,

Have RT Engineering got a better idea about what to include and leave out from the attached documentation yet? Feel free to redirect the needinfo.

Thanks,
Alison

Comment 3 John Kacur 2011-08-30 12:35:22 UTC
http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_MRG/2.0/html-single/Realtime_Tuning_Guide/index.html#sect-Realtime_Tuning_Guide-Realtime_Specific_Tuning-Using_the_ftrace_Utility_for_Tracing_Latencies

The "events" are no longer correct in this version.
The following comments refer to the ftrace section of the guide

Remove "events" from the line below

# cat /sys/kernel/debug/tracing/available_tracers
events wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none

Remove the following section.

events
    Traces system events such as timers, system calls, interrupts, context switches, process wake up and others

In the following section substitute "preemptoff" for "events"
# echo events > /sys/kernel/debug/tracing/current_tracer

In 5. View the trace logs: 

Remove the following line
# cat /sys/kernel/debug/tracing//latency_trace

In 6.
Change
# cat /sys/kernel/debug/tracing//latency_trace > /tmp/lat_trace_log
to
# cat /sys/kernel/debug/tracing/trace > /tmp/trace_log

Comment 13 Lana Brindley 2012-01-26 19:30:51 UTC
This book is now available on redhat.com/docs. Please raise a new bug if you spot any issues.

Thanks,
LKB


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