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![Cody P Schafer](/assets/img/avatar_default.png)
Event parameters are a basic way for partial events to be specified in sysfs with per-event names given to the fields that need to be filled in when using a particular event. It is intended for supporting cases where the single 'cpu' parameter is insufficient. For example, POWER 8 has events for physical sockets/cores/cpus that are accessible from with virtual machines. To keep using the single 'cpu' parameter we'd need to perform a mapping between Linux's cpus and the physical machine's cpus (in this case Linux is running under a hypervisor). This isn't possible because bindings between our cpus and physical cpus may not be fixed, and we probably won't have a "cpu" on each physical cpu. Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Cody P Schafer <dev@codyps.com> Cc: Haren Myneni <hbabu@us.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1420679633-28856-4-git-send-email-sukadev@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
94 lines
3.1 KiB
Text
94 lines
3.1 KiB
Text
What: /sys/devices/cpu/events/
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/sys/devices/cpu/events/branch-misses
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/sys/devices/cpu/events/cache-references
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/sys/devices/cpu/events/cache-misses
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/sys/devices/cpu/events/stalled-cycles-frontend
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/sys/devices/cpu/events/branch-instructions
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/sys/devices/cpu/events/stalled-cycles-backend
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/sys/devices/cpu/events/instructions
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/sys/devices/cpu/events/cpu-cycles
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Date: 2013/01/08
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Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
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Description: Generic performance monitoring events
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A collection of performance monitoring events that may be
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supported by many/most CPUs. These events can be monitored
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using the 'perf(1)' tool.
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The contents of each file would look like:
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event=0xNNNN
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where 'N' is a hex digit and the number '0xNNNN' shows the
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"raw code" for the perf event identified by the file's
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"basename".
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What: /sys/bus/event_source/devices/<pmu>/events/<event>
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Date: 2014/02/24
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Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
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Description: Per-pmu performance monitoring events specific to the running system
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Each file (except for some of those with a '.' in them, '.unit'
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and '.scale') in the 'events' directory describes a single
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performance monitoring event supported by the <pmu>. The name
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of the file is the name of the event.
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File contents:
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<term>[=<value>][,<term>[=<value>]]...
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Where <term> is one of the terms listed under
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/sys/bus/event_source/devices/<pmu>/format/ and <value> is
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a number is base-16 format with a '0x' prefix (lowercase only).
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If a <term> is specified alone (without an assigned value), it
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is implied that 0x1 is assigned to that <term>.
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Examples (each of these lines would be in a seperate file):
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event=0x2abc
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event=0x423,inv,cmask=0x3
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domain=0x1,offset=0x8,starting_index=0xffff
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domain=0x1,offset=0x8,core=?
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Each of the assignments indicates a value to be assigned to a
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particular set of bits (as defined by the format file
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corresponding to the <term>) in the perf_event structure passed
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to the perf_open syscall.
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In the case of the last example, a value replacing "?" would
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need to be provided by the user selecting the particular event.
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This is referred to as "event parameterization". Event
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parameters have the format 'param=?'.
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What: /sys/bus/event_source/devices/<pmu>/events/<event>.unit
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Date: 2014/02/24
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Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
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Description: Perf event units
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A string specifying the English plural numerical unit that <event>
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(once multiplied by <event>.scale) represents.
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Example:
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Joules
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What: /sys/bus/event_source/devices/<pmu>/events/<event>.scale
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Date: 2014/02/24
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Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
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Description: Perf event scaling factors
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A string representing a floating point value expressed in
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scientific notation to be multiplied by the event count
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recieved from the kernel to match the unit specified in the
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<event>.unit file.
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Example:
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2.3283064365386962890625e-10
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This is provided to avoid performing floating point arithmetic
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in the kernel.
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