eae7044b67
So that it can skip events with no sample according to the config value.
This can omit the dummy event in the output of perf report --group.
An example output:
$ sudo perf mem record -a sleep 1
$ sudo perf report --group
Before)
#
# Samples: 232 of events 'cpu/mem-loads,ldlat=30/P, cpu/mem-stores/P, dummy:u'
# Event count (approx.): 3089861
#
# Overhead Command Shared Object Symbol
# ........................ ........... ................. .....................................
#
9.29% 0.00% 0.00% swapper [kernel.kallsyms] [k] update_blocked_averages
5.26% 0.15% 0.00% swapper [kernel.kallsyms] [k] __update_load_avg_se
4.15% 0.00% 0.00% perf-exec [kernel.kallsyms] [k] slab_update_freelist.isra.0
3.87% 0.00% 0.00% perf-exec [kernel.kallsyms] [k] memcg_slab_post_alloc_hook
3.79% 0.17% 0.00% swapper [kernel.kallsyms] [k] enqueue_task_fair
3.63% 0.00% 0.00% sleep [kernel.kallsyms] [k] next_uptodate_page
2.86% 0.00% 0.00% swapper [kernel.kallsyms] [k] __update_load_avg_cfs_rq
2.78% 0.00% 0.00% swapper [kernel.kallsyms] [k] __schedule
2.34% 0.00% 0.00% swapper [kernel.kallsyms] [k] intel_idle
2.32% 0.97% 0.00% swapper [kernel.kallsyms] [k] psi_group_change
After)
#
# Samples: 232 of events 'cpu/mem-loads,ldlat=30/P, cpu/mem-stores/P'
# Event count (approx.): 3089861
#
# Overhead Command Shared Object Symbol
# ................ ........... ................. .....................................
#
9.29% 0.00% swapper [kernel.kallsyms] [k] update_blocked_averages
5.26% 0.15% swapper [kernel.kallsyms] [k] __update_load_avg_se
4.15% 0.00% perf-exec [kernel.kallsyms] [k] slab_update_freelist.isra.0
3.87% 0.00% perf-exec [kernel.kallsyms] [k] memcg_slab_post_alloc_hook
3.79% 0.17% swapper [kernel.kallsyms] [k] enqueue_task_fair
3.63% 0.00% sleep [kernel.kallsyms] [k] next_uptodate_page
2.86% 0.00% swapper [kernel.kallsyms] [k] __update_load_avg_cfs_rq
2.78% 0.00% swapper [kernel.kallsyms] [k] __schedule
2.34% 0.00% swapper [kernel.kallsyms] [k] intel_idle
2.32% 0.97% swapper [kernel.kallsyms] [k] psi_group_change
Now it doesn't have a column for the dummy event.
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240607202918.2357459-5-namhyung@kernel.org
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 reStructuredText 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.