perf-eh_elf/Documentation/perf-top.txt

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Merge tag 'afs-fixes-20180514' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull AFS fixes from David Howells: "Here's a set of patches that fix a number of bugs in the in-kernel AFS client, including: - Fix directory locking to not use individual page locks for directory reading/scanning but rather to use a semaphore on the afs_vnode struct as the directory contents must be read in a single blob and data from different reads must not be mixed as the entire contents may be shuffled about between reads. - Fix address list parsing to handle port specifiers correctly. - Only give up callback records on a server if we actually talked to that server (we might not be able to access a server). - Fix some callback handling bugs, including refcounting, whole-volume callbacks and when callbacks actually get broken in response to a CB.CallBack op. - Fix some server/address rotation bugs, including giving up if we can't probe a server; giving up if a server says it doesn't have a volume, but there are more servers to try. - Fix the decoding of fetched statuses to be OpenAFS compatible. - Fix the handling of server lookups in Cache Manager ops (such as CB.InitCallBackState3) to use a UUID if possible and to handle no server being found. - Fix a bug in server lookup where not all addresses are compared. - Fix the non-encryption of calls that prevents some servers from being accessed (this also requires an AF_RXRPC patch that has already gone in through the net tree). There's also a patch that adds tracepoints to log Cache Manager ops that don't find a matching server, either by UUID or by address" * tag 'afs-fixes-20180514' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Fix the non-encryption of calls afs: Fix CB.CallBack handling afs: Fix whole-volume callback handling afs: Fix afs_find_server search loop afs: Fix the handling of an unfound server in CM operations afs: Add a tracepoint to record callbacks from unlisted servers afs: Fix the handling of CB.InitCallBackState3 to find the server by UUID afs: Fix VNOVOL handling in address rotation afs: Fix AFSFetchStatus decoder to provide OpenAFS compatibility afs: Fix server rotation's handling of fileserver probe failure afs: Fix refcounting in callback registration afs: Fix giving up callbacks on server destruction afs: Fix address list parsing afs: Fix directory page locking
2018-05-15 19:48:36 +02:00
perf-top(1)
===========
NAME
----
perf-top - System profiling tool.
SYNOPSIS
--------
[verse]
'perf top' [-e <EVENT> | --event=EVENT] [<options>]
DESCRIPTION
-----------
This command generates and displays a performance counter profile in real time.
OPTIONS
-------
-a::
--all-cpus::
System-wide collection. (default)
-c <count>::
--count=<count>::
Event period to sample.
-C <cpu-list>::
--cpu=<cpu>::
Monitor only on the list of CPUs provided. Multiple CPUs can be provided as a
comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
Default is to monitor all CPUS.
-d <seconds>::
--delay=<seconds>::
Number of seconds to delay between refreshes.
-e <event>::
--event=<event>::
Select the PMU event. Selection can be a symbolic event name
(use 'perf list' to list all events) or a raw PMU
event (eventsel+umask) in the form of rNNN where NNN is a
hexadecimal event descriptor.
-E <entries>::
--entries=<entries>::
Display this many functions.
-f <count>::
--count-filter=<count>::
Only display functions with more events than this.
--group::
Put the counters into a counter group.
-F <freq>::
--freq=<freq>::
Profile at this frequency. Use 'max' to use the currently maximum
allowed frequency, i.e. the value in the kernel.perf_event_max_sample_rate
sysctl.
-i::
--inherit::
Child tasks do not inherit counters.
-k <path>::
--vmlinux=<path>::
Path to vmlinux. Required for annotation functionality.
--ignore-vmlinux::
Ignore vmlinux files.
-m <pages>::
--mmap-pages=<pages>::
Number of mmap data pages (must be a power of two) or size
specification with appended unit character - B/K/M/G. The
size is rounded up to have nearest pages power of two value.
-p <pid>::
--pid=<pid>::
Profile events on existing Process ID (comma separated list).
-t <tid>::
--tid=<tid>::
Profile events on existing thread ID (comma separated list).
-u::
--uid=::
Record events in threads owned by uid. Name or number.
-r <priority>::
--realtime=<priority>::
Collect data with this RT SCHED_FIFO priority.
--sym-annotate=<symbol>::
Annotate this symbol.
-K::
--hide_kernel_symbols::
Hide kernel symbols.
-U::
--hide_user_symbols::
Hide user symbols.
--demangle-kernel::
Demangle kernel symbols.
-D::
--dump-symtab::
Dump the symbol table used for profiling.
-v::
--verbose::
Be more verbose (show counter open errors, etc).
-z::
--zero::
Zero history across display updates.
-s::
--sort::
Sort by key(s): pid, comm, dso, symbol, parent, srcline, weight,
local_weight, abort, in_tx, transaction, overhead, sample, period.
Please see description of --sort in the perf-report man page.
--fields=::
Specify output field - multiple keys can be specified in CSV format.
Following fields are available:
overhead, overhead_sys, overhead_us, overhead_children, sample and period.
Also it can contain any sort key(s).
By default, every sort keys not specified in --field will be appended
automatically.
-n::
--show-nr-samples::
Show a column with the number of samples.
--show-total-period::
Show a column with the sum of periods.
--dsos::
Only consider symbols in these dsos. This option will affect the
percentage of the overhead column. See --percentage for more info.
--comms::
Only consider symbols in these comms. This option will affect the
percentage of the overhead column. See --percentage for more info.
--symbols::
Only consider these symbols. This option will affect the
percentage of the overhead column. See --percentage for more info.
-M::
--disassembler-style=:: Set disassembler style for objdump.
--source::
Interleave source code with assembly code. Enabled by default,
disable with --no-source.
--asm-raw::
Show raw instruction encoding of assembly instructions.
-g::
Enables call-graph (stack chain/backtrace) recording.
--call-graph [mode,type,min[,limit],order[,key][,branch]]::
Setup and enable call-graph (stack chain/backtrace) recording,
implies -g. See `--call-graph` section in perf-record and
perf-report man pages for details.
--children::
Accumulate callchain of children to parent entry so that then can
show up in the output. The output will have a new "Children" column
and will be sorted on the data. It requires -g/--call-graph option
enabled. See the `overhead calculation' section for more details.
Enabled by default, disable with --no-children.
--max-stack::
Set the stack depth limit when parsing the callchain, anything
beyond the specified depth will be ignored. This is a trade-off
between information loss and faster processing especially for
workloads that can have a very long callchain stack.
Default: /proc/sys/kernel/perf_event_max_stack when present, 127 otherwise.
--ignore-callees=<regex>::
Ignore callees of the function(s) matching the given regex.
This has the effect of collecting the callers of each such
function into one place in the call-graph tree.
--percent-limit::
Do not show entries which have an overhead under that percent.
(Default: 0).
--percentage::
Determine how to display the overhead percentage of filtered entries.
Filters can be applied by --comms, --dsos and/or --symbols options and
Zoom operations on the TUI (thread, dso, etc).
"relative" means it's relative to filtered entries only so that the
sum of shown entries will be always 100%. "absolute" means it retains
the original value before and after the filter is applied.
-w::
--column-widths=<width[,width...]>::
Force each column width to the provided list, for large terminal
readability. 0 means no limit (default behavior).
--proc-map-timeout::
When processing pre-existing threads /proc/XXX/mmap, it may take
a long time, because the file may be huge. A time out is needed
in such cases.
This option sets the time out limit. The default value is 500 ms.
-b::
--branch-any::
Enable taken branch stack sampling. Any type of taken branch may be sampled.
This is a shortcut for --branch-filter any. See --branch-filter for more infos.
-j::
--branch-filter::
Enable taken branch stack sampling. Each sample captures a series of consecutive
taken branches. The number of branches captured with each sample depends on the
underlying hardware, the type of branches of interest, and the executed code.
It is possible to select the types of branches captured by enabling filters.
For a full list of modifiers please see the perf record manpage.
The option requires at least one branch type among any, any_call, any_ret, ind_call, cond.
The privilege levels may be omitted, in which case, the privilege levels of the associated
event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege
levels are subject to permissions. When sampling on multiple events, branch stack sampling
is enabled for all the sampling events. The sampled branch type is the same for all events.
The various filters must be specified as a comma separated list: --branch-filter any_ret,u,k
Note that this feature may not be available on all processors.
--raw-trace::
When displaying traceevent output, do not use print fmt or plugins.
--hierarchy::
Enable hierarchy output.
--force::
Don't do ownership validation.
--num-thread-synthesize::
The number of threads to run when synthesizing events for existing processes.
By default, the number of threads equals to the number of online CPUs.
INTERACTIVE PROMPTING KEYS
--------------------------
[d]::
Display refresh delay.
[e]::
Number of entries to display.
[E]::
Event to display when multiple counters are active.
[f]::
Profile display filter (>= hit count).
[F]::
Annotation display filter (>= % of total).
[s]::
Annotate symbol.
[S]::
Stop annotation, return to full profile display.
[K]::
Hide kernel symbols.
[U]::
Hide user symbols.
[z]::
Toggle event count zeroing across display updates.
[qQ]::
Quit.
Pressing any unmapped key displays a menu, and prompts for input.
include::callchain-overhead-calculation.txt[]
SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-report[1]