From 1a891cf19cdfb645827969cc6aeaeebdefeb87b2 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 12 Jun 2013 13:16:25 -0400 Subject: 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 Tested-by: Arend van Spriel Signed-off-by: Steven Rostedt --- Documentation/trace/events.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/trace') diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt index bb24c2a0e870..41911240c65c 100644 --- a/Documentation/trace/events.txt +++ b/Documentation/trace/events.txt @@ -183,7 +183,7 @@ The relational-operators depend on the type of the field being tested: The operators available for numeric fields are: -==, !=, <, <=, >, >= +==, !=, <, <=, >, >=, & And for string fields they are: -- cgit v1.2.3