mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-04-13 01:39:06 +08:00
b6d8b858db
perf test 17 'Setup struct perf_event_attr' fails on s390 z/VM guest,
using linux-next kernel.
Root cause is the fall-back from hardware counter cycles
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
size 136
config 0 (PERF_COUNT_HW_CPU_CYCLES)
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|ADDR|PERIOD|DATA_SRC
read_format ID|LOST
which returns -ENOENT on s390 z/VM guest. This causes the code to fall
back to software counter task-clock, as can be seen in the debug output:
------------------------------------------------------------
perf_event_attr:
type 1 (PERF_TYPE_SOFTWARE)
size 136
config 0x1 (PERF_COUNT_SW_TASK_CLOCK) <-here
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|ADDR|PERIOD|DATA_SRC
read_format ID|LOST
This succeeds on s390 z/VM guest.
This successful installation of the counter task-clock is not listed in
the expected results and the test case fails.
This is caused by commit eb2eac0c7b ("perf evsel: Fallback to
"task-clock" when not system wide") which introduced fall back from
event 'cycles' to event 'task-clock'.
To fix this on s390 allow event number 0 (cycles) and event number 1
(task-clock) as expected result.
Output before:
# ./perf test -Fv 17
17: Setup struct perf_event_attr :
--- start ---
running './tests/attr/test-stat-group1'
unsupp './tests/attr/test-stat-group1'
running './tests/attr/test-record-graph-default'
test limitation '!aarch64'
excluded architecture list ['aarch64']
expected config=0, got 1
FAILED './tests/attr/test-record-graph-default' - match failure
---- end ----
Setup struct perf_event_attr: FAILED!
#
Output after:
# ./perf test -F 17
17: Setup struct perf_event_attr : Ok
#
Fixes: eb2eac0c7b ("perf evsel: Fallback to "task-clock" when not system wide")
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20231219143235.1075522-1-tmricht@linux.ibm.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.