linux/tools
Changbin Du 74298dd8ac perf ftrace: Detect whether ftrace is enabled on system
To make error messages more accurate, this change detects whether ftrace is
enabled on system by checking trace file "set_ftrace_pid".

Before:

  # perf ftrace
  failed to reset ftrace
  #

After:

  # perf ftrace
  ftrace is not supported on this system
  #

Committer testing:

Doing it in an unprivileged toolbox container on Fedora 40:

Before:

  acme@number:~/git/perf-tools-next$ toolbox enter perf
  ⬢[acme@toolbox perf-tools-next]$ sudo su -
  ⬢[root@toolbox ~]# ~acme/bin/perf ftrace
  failed to reset ftrace
  ⬢[root@toolbox ~]#

After this patch:

  ⬢[root@toolbox ~]# ~acme/bin/perf ftrace
  ftrace is not supported on this system
  ⬢[root@toolbox ~]#

Maybe we could check if we are in such as situation, inside an
unprivileged container, and provide a HINT line?

Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Changbin Du <changbin.du@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240911100126.900779-1-changbin.du@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-09-11 09:35:35 -03:00
..
accounting
arch tools/include: Sync arm64 headers with the kernel sources 2024-08-07 10:59:07 -07:00
bootconfig
bpf tools/resolve_btfids: Fix comparison of distinct pointer types warning in resolve_btfids 2024-07-22 16:35:30 +02:00
build perf build: Remove unused feature test target 2024-09-10 17:32:47 -03:00
certs
cgroup
counter
crypto
debugging
firewire
firmware
gpio gpio: add sloppy logic analyzer using polling 2024-07-01 10:54:11 +02:00
hv tools: hv: suppress the invalid warning for packed member alignment 2024-05-28 05:27:35 +00:00
iio
include perf: cs-etm: Support version 0.1 of HW_ID packets 2024-08-29 15:56:13 -03:00
kvm/kvm_stat
laptop
leds
lib libsubcmd: Don't free the usage string 2024-09-04 09:54:24 -03:00
memory-model kcsan: Add __data_racy documentation and module description 2024-07-15 15:44:40 -07:00
mm tools/mm: introduce a tool to assess swap entry allocation for thp_swapout 2024-07-10 12:14:51 -07:00
net/ynl tools/net/ynl: fix cli.py --subscribe feature 2024-09-05 14:56:45 -07:00
objtool - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN 2024-07-21 17:15:46 -07:00
pci
pcmcia
perf perf ftrace: Detect whether ftrace is enabled on system 2024-09-11 09:35:35 -03:00
power turbostat release 2024.07.26 2024-07-28 10:52:15 -07:00
rcu tools/rcu: Add rcu-updaters.sh script 2024-06-06 11:44:42 -07:00
scripts
sound
spi
testing bpf-6.11-rc7 2024-09-05 20:10:53 -07:00
thermal
time
tracing rtla/osnoise: Prevent NULL dereference in error handling 2024-08-09 13:03:15 -04:00
usb
verification tools/verification: Use pkg-config in lib_setup of Makefile.config 2024-07-17 13:14:51 -07:00
virtio tools/virtio: creating pipe assertion in vringh_test 2024-07-04 11:00:31 -04:00
wmi
workqueue
writeback
Makefile