[PATCH v6 5/5] tracing: docs: Update histogram doc for .percent/.graph and 'nohitcount'

From: Masami Hiramatsu (Google)
Date: Tue Oct 18 2022 - 11:50:09 EST


From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Update histogram document for .percent/.graph suffixes and 'nohitcount'
option.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Reviewed-by: Tom Zanussi <zanussi@xxxxxxxxxx>
Tested-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
Documentation/trace/histogram.rst | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index 859fd1b76c63..b2da4e9c62e8 100644
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -25,7 +25,7 @@ Documentation written by Tom Zanussi

hist:keys=<field1[,field2,...]>[:values=<field1[,field2,...]>]
[:sort=<field1[,field2,...]>][:size=#entries][:pause][:continue]
- [:clear][:name=histname1][:<handler>.<action>] [if <filter>]
+ [:clear][:name=histname1][:nohitcount][:<handler>.<action>] [if <filter>]

When a matching event is hit, an entry is added to a hash table
using the key(s) and value(s) named. Keys and values correspond to
@@ -79,6 +79,8 @@ Documentation written by Tom Zanussi
.log2 display log2 value rather than raw number
.buckets=size display grouping of values rather than raw number
.usecs display a common_timestamp in microseconds
+ .percent display a number of percentage value
+ .graph display a bar-graph of a value
============= =================================================

Note that in general the semantics of a given field aren't
@@ -137,6 +139,12 @@ Documentation written by Tom Zanussi
existing trigger, rather than via the '>' operator, which will cause
the trigger to be removed through truncation.

+ The 'nohitcount' (or NOHC) parameter will suppress display of
+ raw hitcount in the histogram. This option requires at least one
+ value field which is not a 'raw hitcount'. For example,
+ 'hist:...:vals=hitcount:nohitcount' is rejected, but
+ 'hist:...:vals=hitcount.percent:nohitcount' is OK.
+
- enable_hist/disable_hist

The enable_hist and disable_hist triggers can be used to have one