edcaa47958
Add a 'ping' command to verify that the 'perf record' session is up and
operational.
It's used in the following patches via test code to make sure 'perf
record' is ready to receive signals.
Example:
# cat ~/.perfconfig
[daemon]
base=/opt/perfdata
[session-cycles]
run = -m 10M -e cycles --overwrite --switch-output -a
[session-sched]
run = -m 20M -e sched:* --overwrite --switch-output -a
Start the daemon:
# perf daemon start
Ping all sessions:
# perf daemon ping
OK cycles
OK sched
Ping specific session:
# perf daemon ping --session sched
OK sched
Committer notes:
Fixed up bug pointed by clang:
Buggy:
if (!pollfd.revents & POLLIN)
Correct code:
if (!(pollfd.revents & POLLIN))
clang warning:
builtin-daemon.c:560:6: error: logical not is only applied to the left hand side of this bitwise operator [-Werror,-Wlogical-not-parentheses]
if (!pollfd.revents & POLLIN) {
^ ~
builtin-daemon.c:560:6: note: add parentheses after the '!' to evaluate the bitwise operator first
Also use designated initialized with pollfd, i.e.:
struct pollfd pollfd = { .events = POLLIN, };
Instead of:
struct pollfd pollfd = { 0, };
To get past:
builtin-daemon.c:510:30: error: missing field 'events' initializer [-Werror,-Wmissing-field-initializers]
struct pollfd pollfd = { 0, };
^
1 error generated.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-16-jolsa@kernel.org
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.