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[Bug 1560482] [NEW] perf: 24x7: Eliminate domain name suffix in event names

To: kernel-packages@xxxxxxxxxxxxxxxxxxx
From: Launchpad Bug Tracker <1560482@xxxxxxxxxxxxxxxxxx>
Date: Tue, 22 Mar 2016 23:16:06 -0000
Reply-to: Bug 1560482 <1560482@xxxxxxxxxxxxxxxxxx>
Sender: bounces@xxxxxxxxxxxxx

You have been subscribed to a public bug:

Events in the 24x7 counters can belong to different domains like
core, chip, virtual CPU home core, etc. To monitor an event, the
user must specify the required parameters for the event, which
include its name, the chip/core on which to monitor the event
as well as the domain.

Currently the event is specified to the perf tool as:

        'hv_24x7/HPM_0THRD_NON_IDLE_CCYC__PHYS_CORE,core=1/' \

where the event name is 'HPM_0THRD_NON_IDLE_CCYC', the suffix
'__PHYS_CORE' specifies the domain, and 'core=1' specifies the 
core. This is inconsistent in that one parameter is specified
as a suffix and the other in a parameter=value format.

To simplify the usage, we can eliminate the suffix and let the 
user specify the domain also in the param=value format. While
the domain indices are "well known" or nearly fixed in value,
we could display the domain indices in sysfs as a reference for 
the users:

        $ cat /sys/bus/event_source/devices/hv_24x7/interface/domains
        1: Physical Chip
        2: Physical Core
        3: VCPU Home Core
        4: VCPU Home Chip
        5: VCPU Home Node
        6: VCPU Remote Node

Using these the perf event can now be identified as

        hv_24x7/HPM_0THRD_NON_IDLE_CCYC,domain=2,core=1

. This feature is implemented by the following commits which have now
been merged into mainline:

        d34171e: powerpc/perf/hv-24x7: Display domain indices in sysfs
        8f69dc7: powerpc/perf/24x7: Eliminate domain suffix in event names

== Comment: #1 - Sukadev Bhattiprolu <suka@xxxxxxxxxx> - 2016-03-21 15:26:33 ==
Following two upstream commits are also related 24x7 and could
be included in this feature:

e5a5886: powerpc/perf/hv-24x7: Fix usage with chip events.
2b206ee: powerpc/perf/hv-24x7: Display change in counter values

** Affects: linux (Ubuntu)
     Importance: Undecided
     Assignee: Taco Screen team (taco-screen-team)
         Status: Confirmed


** Tags: architecture-ppc64 bot-comment bugnameltc-139405 severity-medium targetmilestone-inin16041
-- 
perf: 24x7: Eliminate domain name suffix in event names
https://bugs.launchpad.net/bugs/1560482
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