perf-list(1) — Linux manual page


PERF-LIST(1)                     perf Manual                    PERF-LIST(1)

NAME         top

       perf-list - List all symbolic event types

SYNOPSIS         top

       perf list [--no-desc] [--long-desc]

DESCRIPTION         top

       This command displays the symbolic event types which can be selected
       in the various perf commands with the -e option.

OPTIONS         top

       -d, --desc
           Print extra event descriptions. (default)

           Don’t print descriptions.

       -v, --long-desc
           Print longer event descriptions.

           Enable debugging output.

           Print how named events are resolved internally into perf events,
           and also any extra expressions computed by perf stat.

           Print deprecated events. By default the deprecated events are


       Events can optionally have a modifier by appending a colon and one or
       more modifiers. Modifiers allow the user to restrict the events to be
       counted. The following modifiers exist:

           u - user-space counting
           k - kernel counting
           h - hypervisor counting
           I - non idle counting
           G - guest counting (in KVM guests)
           H - host counting (not in KVM guests)
           p - precise level
           P - use maximum detected precise level
           S - read sample value (PERF_SAMPLE_READ)
           D - pin the event to the PMU
           W - group is weak and will fallback to non-group if not schedulable,

       The p modifier can be used for specifying how precise the instruction
       address should be. The p modifier can be specified multiple times:

           0 - SAMPLE_IP can have arbitrary skid
           1 - SAMPLE_IP must have constant skid
           2 - SAMPLE_IP requested to have 0 skid
           3 - SAMPLE_IP must have 0 skid, or uses randomization to avoid
               sample shadowing effects.

       For Intel systems precise event sampling is implemented with PEBS
       which supports up to precise-level 2, and precise level 3 for some
       special cases

       On AMD systems it is implemented using IBS (up to precise-level 2).
       The precise modifier works with event types 0x76 (cpu-cycles, CPU
       clocks not halted) and 0xC1 (micro-ops retired). Both events map to
       IBS execution sampling (IBS op) with the IBS Op Counter Control bit
       (IbsOpCntCtl) set respectively (see AMD64 Architecture Programmer’s
       Manual Volume 2: System Programming, 13.3 Instruction-Based
       Sampling). Examples to use IBS:

           perf record -a -e cpu-cycles:p ...    # use ibs op counting cycles
           perf record -a -e r076:p ...          # same as -e cpu-cycles:p
           perf record -a -e r0C1:p ...          # use ibs op counting micro-ops


       Even when an event is not available in a symbolic form within perf
       right now, it can be encoded in a per processor specific way.

       For instance For x86 CPUs NNN represents the raw register encoding
       with the layout of IA32_PERFEVTSELx MSRs (see [Intel® 64 and IA-32
       Architectures Software Developer’s Manual Volume 3B: System
       Programming Guide] Figure 30-1 Layout of IA32_PERFEVTSELx MSRs) or
       AMD’s PerfEvtSeln (see [AMD64 Architecture Programmer’s Manual Volume
       2: System Programming], Page 344, Figure 13-7 Performance
       Event-Select Register (PerfEvtSeln)).

       Note: Only the following bit fields can be set in x86 counter
       registers: event, umask, edge, inv, cmask. Esp. guest/host only and
       OS/user mode flags must be setup using EVENT MODIFIERS.


       If the Intel docs for a QM720 Core i7 describe an event as:

           Event  Umask  Event Mask
           Num.   Value  Mnemonic    Description                        Comment

           A8H      01H  LSD.UOPS    Counts the number of micro-ops     Use cmask=1 and
                                     delivered by loop stream detector  invert to count

       raw encoding of 0x1A8 can be used:

           perf stat -e r1a8 -a sleep 1
           perf record -e r1a8 ...

       It’s also possible to use pmu syntax:

           perf record -e r1a8 -a sleep 1
           perf record -e cpu/r1a8/ ...
           perf record -e cpu/r0x1a8/ ...

       You should refer to the processor specific documentation for getting
       these details. Some of them are referenced in the SEE ALSO section

ARBITRARY PMUS         top

       perf also supports an extended syntax for specifying raw parameters
       to PMUs. Using this typically requires looking up the specific event
       in the CPU vendor specific documentation.

       The available PMUs and their raw parameters can be listed with

           ls /sys/devices/*/format

       For example the raw event "LSD.UOPS" core pmu event above could be
       specified as

           perf stat -e cpu/event=0xa8,umask=0x1,name=LSD.UOPS_CYCLES,cmask=0x1/ ...

           or using extended name syntax

           perf stat -e cpu/event=0xa8,umask=0x1,cmask=0x1,name=\'LSD.UOPS_CYCLES:cmask=0x1\'/ ...

PER SOCKET PMUS         top

       Some PMUs are not associated with a core, but with a whole CPU
       socket. Events on these PMUs generally cannot be sampled, but only
       counted globally with perf stat -a. They can be bound to one logical
       CPU, but will measure all the CPUs in the same socket.

       This example measures memory bandwidth every second on the first
       memory controller on socket 0 of a Intel Xeon system

           perf stat -C 0 -a uncore_imc_0/cas_count_read/,uncore_imc_0/cas_count_write/ -I 1000 ...

       Each memory controller has its own PMU. Measuring the complete system
       bandwidth would require specifying all imc PMUs (see perf list
       output), and adding the values together. To simplify creation of
       multiple events, prefix and glob matching is supported in the PMU
       name, and the prefix uncore_ is also ignored when performing the
       match. So the command above can be expanded to all memory controllers
       by using the syntaxes:

           perf stat -C 0 -a imc/cas_count_read/,imc/cas_count_write/ -I 1000 ...
           perf stat -C 0 -a *imc*/cas_count_read/,*imc*/cas_count_write/ -I 1000 ...

       This example measures the combined core power every second

           perf stat -I 1000 -e power/energy-cores/  -a


       For non root users generally only context switched PMU events are
       available. This is normally only the events in the cpu PMU, the
       predefined events like cycles and instructions and some software

       Other PMUs and global measurements are normally root only. Some event
       qualifiers, such as "any", are also root only.

       This can be overridden by setting the kernel.perf_event_paranoid
       sysctl to -1, which allows non root to use these events.

       For accessing trace point events perf needs to have read access to
       /sys/kernel/debug/tracing, even when perf_event_paranoid is in a
       relaxed setting.

TRACING         top

       Some PMUs control advanced hardware tracing capabilities, such as
       Intel PT, that allows low overhead execution tracing. These are
       described in a separate intel-pt.txt document.


       Some pmu events listed by perf-list will be displayed with ? in them.
       For example:


       This means that when provided as an event, a value for ? must also be
       supplied. For example:

           perf stat -C 0 -e 'hv_gpci/dtbp_ptitc,phys_processor_idx=0x2/' ...


       It is also possible to add extra qualifiers to an event:


       Sums up the event counts for all hardware threads in a core, e.g.:

           perf stat -e cpu/event=0,umask=0x3,percore=1/

EVENT GROUPS         top

       Perf supports time based multiplexing of events, when the number of
       events active exceeds the number of hardware performance counters.
       Multiplexing can cause measurement errors when the workload changes
       its execution profile.

       When metrics are computed using formulas from event counts, it is
       useful to ensure some events are always measured together as a group
       to minimize multiplexing errors. Event groups can be specified using
       { }.

           perf stat -e '{instructions,cycles}' ...

       The number of available performance counters depend on the CPU. A
       group cannot contain more events than available counters. For example
       Intel Core CPUs typically have four generic performance counters for
       the core, plus three fixed counters for instructions, cycles and
       ref-cycles. Some special events have restrictions on which counter
       they can schedule, and may not support multiple instances in a single
       group. When too many events are specified in the group some of them
       will not be measured.

       Globally pinned events can limit the number of counters available for
       other groups. On x86 systems, the NMI watchdog pins a counter by
       default. The nmi watchdog can be disabled as root with

           echo 0 > /proc/sys/kernel/nmi_watchdog

       Events from multiple different PMUs cannot be mixed in a group, with
       some exceptions for software events.


       perf also supports group leader sampling using the :S specifier.

           perf record -e '{cycles,instructions}:S' ...
           perf report --group

       Normally all events in an event group sample, but with :S only the
       first event (the leader) samples, and it only reads the values of the
       other events in the group.

       However, in the case AUX area events (e.g. Intel PT or CoreSight),
       the AUX area event must be the leader, so then the second event
       samples, not the first.

OPTIONS         top

       Without options all known events will be listed.

       To limit the list use:

        1. hw or hardware to list hardware events such as cache-misses, etc.

        2. sw or software to list software events such as context switches,

        3. cache or hwcache to list hardware cache events such as
           L1-dcache-loads, etc.

        4. tracepoint to list all tracepoint events, alternatively use
           subsys_glob:event_glob to filter by tracepoint subsystems such as
           sched, block, etc.

        5. pmu to print the kernel supplied PMU events.

        6. sdt to list all Statically Defined Tracepoint events.

        7. metric to list metrics

        8. metricgroup to list metricgroups with metrics.

        9. If none of the above is matched, it will apply the supplied glob
           to all events, printing the ones that match.

       10. As a last resort, it will do a substring search in all event

       One or more types can be used at the same time, listing the events
       for the types specified.

       Support raw format:

        1. --raw-dump, shows the raw-dump of all the events.

        2. --raw-dump [hw|sw|cache|tracepoint|pmu|event_glob], shows the
           raw-dump of a certain kind of events.

SEE ALSO         top

       perf-stat(1), perf-top(1), perf-record(1), Intel® 64 and IA-32
       Architectures Software Developer’s Manual Volume 3B: System
       Programming Guide[1], AMD64 Architecture Programmer’s Manual Volume
       2: System Programming[2]

NOTES         top

        1. Intel® 64 and IA-32 Architectures Software Developer’s Manual
           Volume 3B: System Programming Guide

        2. AMD64 Architecture Programmer’s Manual Volume 2: System

COLOPHON         top

       This page is part of the perf (Performance analysis tools for Linux
       (in Linux source tree)) project.  Information about the project can
       be found at ⟨⟩.  If
       you have a bug report for this manual page, send it to  This page was obtained from the
       project's upstream Git repository
       ⟨⟩ on
       2020-08-13.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-08-12.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
       there is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

perf                             2020-07-30                     PERF-LIST(1)

Pages that refer to this page: perf(1)perf-evlist(1)perf-record(1)perf-stat(1)perf-top(1)