kernel_optimize_test/Documentation/trace
Steven Rostedt 1a891cf19c tracing: Add binary '&' filter for events
There are some cases when filtering on a set flag of a field of a tracepoint
is useful. But currently the only filtering commands for numbered fields
is ==, !=, <, <=, >, >=. This does not help when you just want to trace if
a specific flag is set. For example:

 > # sudo trace-cmd record -e brcmfmac:brcmf_dbg -f 'level & 0x40000'
 > disable all
 > enable brcmfmac:brcmf_dbg
 > path = /sys/kernel/debug/tracing/events/brcmfmac/brcmf_dbg/enable
 > (level & 0x40000)
 > ^
 > parse_error: Invalid operator
 >

When trying to trace brcmf_dbg when level has its 1 << 18 bit set, the
filter fails to perform.

By allowing a binary '&' operation, this gives the user the ability to
test a bit.

Note, a binary '|' is not added, as it doesn't make sense as fields must
be compared to constants (for now), and ORing a constant will always return
true.

Link: http://lkml.kernel.org/r/1371057385.9844.261.camel@gandalf.local.home

Suggested-by: Arend van Spriel <arend@broadcom.com>
Tested-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-06-19 23:30:40 -04:00
..
postprocess mm-tracepoint: rename page-free events 2012-01-10 16:30:41 -08:00
events-kmem.txt mm-tracepoint: rename page-free events 2012-01-10 16:30:41 -08:00
events-power.txt PM / tracing: remove deprecated power trace API 2013-01-26 00:39:12 +01:00
events.txt tracing: Add binary '&' filter for events 2013-06-19 23:30:40 -04:00
ftrace-design.txt tracing/syscalls: Allow arch specific syscall symbol matching 2011-02-07 21:29:03 -05:00
ftrace.txt tracing: Add function probe to trigger a ftrace dump of current CPU trace 2013-06-11 18:38:48 -04:00
function-graph-fold.vim tracing: Add vim script to enable folding for function_graph traces 2009-08-26 00:32:04 -04:00
kprobetrace.txt doc: fix old config name of kprobetrace 2012-09-27 12:11:29 +02:00
mmiotrace.txt Documentation: Update mmiotrace.txt 2009-12-20 06:18:23 +01:00
ring-buffer-design.txt Fix common misspellings 2011-03-31 11:26:23 -03:00
tracepoint-analysis.txt mm-tracepoint: fix documentation and examples 2012-01-10 16:30:41 -08:00
tracepoints.txt doc: Remove text on tracepoint samples 2013-03-21 10:58:03 +01:00
uprobetracer.txt uretprobes: Documentation update 2013-04-13 15:31:59 +02:00