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authorMichael Ellerman <michael@ellerman.id.au>2013-05-10 17:33:00 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-05-29 16:11:40 +0300
commitfd851780e61ac36e8d59fe87cca01a2e673930ff (patch)
treec60086d7d8d423fca44f217941a0497ff7068c48 /Documentation/ABI
parent54aa3b99982a6e5f12b52b394244b5086a330a34 (diff)
perf: Expand definition of sysfs format attribute
Make it explicit that the format attributes may define overlapping bit ranges. Unfortunately this was left unspecified originally, and all the examples show non-overlapping ranges. I don't believe this is an ABI change, as we are defining something that was previously undefined, but others may disagree. The POWER8 PMU would like to define overlapping ranges, as bit ranges in the event code have different meanings for certain events. It will also allow us to define an overarching "event" field, that encompasses all others. As far as I can see perf is comfortable with this change, however I am not sure if there are any other users of the interface. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1368199980-20283-1-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-event_source-devices-format6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-format b/Documentation/ABI/testing/sysfs-bus-event_source-devices-format
index 079afc71363d..77f47ff5ee02 100644
--- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-format
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-format
@@ -9,6 +9,12 @@ Description:
we want to export, so that userspace can deal with sane
name/value pairs.
+ Userspace must be prepared for the possibility that attributes
+ define overlapping bit ranges. For example:
+ attr1 = 'config:0-23'
+ attr2 = 'config:0-7'
+ attr3 = 'config:12-35'
+
Example: 'config1:1,6-10,44'
Defines contents of attribute that occupies bits 1,6-10,44 of
perf_event_attr::config1.