If events in a group explicitly set a frequency or period with leader
sampling, don't disable the samples on those events.
Prior to 5.8:
perf record -e '{cycles/period=12345000/,instructions/period=6789000/}:S'
would clear the attributes then apply the config terms. In commit
5f34278867 leader sampling configuration was moved to after applying the
config terms, in the example, making the instructions' event have its period
cleared.
This change makes it so that sampling is only disabled if configuration
terms aren't present.
Committer testing:
Before:
# perf record -e '{cycles/period=1/,instructions/period=2/}:S' sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.051 MB perf.data (6 samples) ]
#
# perf evlist -v
cycles/period=1/: size: 120, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|READ|ID, read_format: ID|GROUP, disabled: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
instructions/period=2/: size: 120, config: 0x1, sample_type: IP|TID|TIME|READ|ID, read_format: ID|GROUP, sample_id_all: 1, exclude_guest: 1
#
After:
# perf record -e '{cycles/period=1/,instructions/period=2/}:S' sleep 0.0001
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.052 MB perf.data (4 samples) ]
# perf evlist -v
cycles/period=1/: size: 120, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|READ|ID, read_format: ID|GROUP, disabled: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
instructions/period=2/: size: 120, config: 0x1, { sample_period, sample_freq }: 2, sample_type: IP|TID|TIME|READ|ID, read_format: ID|GROUP, sample_id_all: 1, exclude_guest: 1
#
Fixes: 5f34278867 ("perf evlist: Move leader-sampling configuration")
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yonghong Song <yhs@fb.com>
Link: http://lore.kernel.org/lkml/20200912025655.1337192-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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.
3b0a18c1aa