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Ian Rogers ec5c5b3d2c perf metric: Encode and use metric-id as qualifier
For a metric like IPC a group of events like {instructions,cycles}:W
would be formed.

If the events names were changed in parsing then the metric expression
parser would fail to find them.

This change makes the event encoding be something like:

  {instructions/metric-id=instructions/, cycles/metric-id=cycles/}

and then uses the evsel's stable metric-id value to locate the events.

This fixes the case that an event is restricted to user because of the
paranoia setting:

  $ echo 2 > /proc/sys/kernel/perf_event_paranoid
  $ perf stat -M IPC /bin/true
   Performance counter stats for '/bin/true':

             150,298      inst_retired.any:u        #      0.77 IPC
             187,095      cpu_clk_unhalted.thread:u

         0.002042731 seconds time elapsed

         0.000000000 seconds user
         0.002377000 seconds sys

Adding the metric-id as a qualifier has a complication in that
qualifiers will become embedded in qualifiers.

For example, msr/tsc/ could become msr/tsc,metric-id=msr/tsc// which
will fail parse-events.

To solve this problem the metric is encoded and decoded for the
metric-id with !<num> standing in for an encoded value.

Previously ! wasn't parsed.

With this msr/tsc/ becomes msr/tsc,metric-id=msr!3tsc!3/

The metric expression parser is changed so that @ isn't changed to /,
instead this is done when the ID is encoded for parse events.

metricgroup__add_metric_non_group() and metricgroup__add_metric_weak_group()
need to inject the metric-id qualifier, so to avoid repetition they are
merged into a single metricgroup__build_event_string with error codes
more rigorously checked.

stat-shadow's prepare_metric() uses the metric-id to match the metricgroup
code.

As "metric-id=..." is added to all events, it is adding during testing
with the fake PMU.

This complicates pmu_str_check code as PE_PMU_EVENT_FAKE won't match as
part of a configuration.

The testing fake PMU case is fixed so that if a known qualifier with an
! is parsed then it isn't reported as a fake PMU.

This is sufficient to pass all testing but it and the original mechanism
are somewhat brittle.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Antonov <alexander.antonov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Kilroy <andrew.kilroy@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Denys Zagorui <dzagorui@cisco.com>
Cc: Fabian Hemmer <copy@copy.sh>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joakim Zhang <qiangqing.zhang@nxp.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nicholas Fraser <nfraser@codeweavers.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: ShihCheng Tu <mrtoastcheng@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Wan Jiabing <wanjiabing@vivo.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20211015172132.1162559-17-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-10-20 10:57:05 -03:00
Documentation Networking fixes for 5.15-rc5, including fixes from xfrm, bpf, 2021-10-07 09:50:31 -07:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
arch ARM: SoC fixes for v5.15 2021-10-07 14:01:29 -07:00
block block-5.15-2021-10-01 2021-10-02 11:00:36 -07:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-08-30 12:57:10 -07:00
drivers ARM: SoC fixes for v5.15 2021-10-07 14:01:29 -07:00
fs Bug fixes for NFSD error handling paths 2021-10-07 14:11:40 -07:00
include ARM: SoC fixes for v5.15 2021-10-07 14:01:29 -07:00
init Merge branch 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-09-24 10:18:07 -07:00
ipc ipc: remove memcg accounting for sops objects in do_semtimedop() 2021-09-14 10:22:11 -07:00
kernel Networking fixes for 5.15-rc5, including fixes from xfrm, bpf, 2021-10-07 09:50:31 -07:00
lib lib/zlib_inflate/inffast: check config in C to avoid unused function warning 2021-09-24 16:13:35 -07:00
mm mm: fix uninitialized use in overcommit_policy_handler 2021-09-24 16:13:35 -07:00
net Bug fixes for NFSD error handling paths 2021-10-07 14:11:40 -07:00
samples samples/bpf: Relicense bpf_insn.h as GPL-2.0-only OR BSD-2-Clause 2021-09-29 16:03:55 +02:00
scripts kasan: always respect CONFIG_KASAN_STACK 2021-09-24 16:13:35 -07:00
security Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ 2021-10-07 12:44:41 +01:00
sound ALSA: pcsp: Make hrtimer forwarding more robust 2021-09-28 10:58:08 +02:00
tools perf metric: Encode and use metric-id as qualifier 2021-10-20 10:57:05 -03:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt KVM: Remove tlbs_dirty 2021-09-23 11:01:12 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update email address of Matthias Fuchs and Thomas Körper 2021-08-19 09:39:44 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ARM: SoC fixes for v5.15 2021-10-07 14:01:29 -07:00
Makefile Linux 5.15-rc4 2021-10-03 14:08:47 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.