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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-11-21 23:42:00 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-11-22 04:25:44 +0300 |
| commit | 11c6cbe706f218a8dc7e1f962f12b3a52ddd33a9 (patch) | |
| tree | 447b75de74aabf184590ef63aeae5773e96a39e0 /tools/build/Makefile.feature | |
| parent | d47d77c3f008d3cf02c6ce92ef4f6e32ca270351 (diff) | |
| download | linux-11c6cbe706f218a8dc7e1f962f12b3a52ddd33a9.tar.xz | |
tools build feature: Check if eventfd() is available
A new 'perf bench epoll' will use this, and to disable it for older
systems, add a feature test for this API.
This is just a simple program that if successfully compiled, means that
the feature is present, at least at the library level, in a build that
sets the output directory to /tmp/build/perf (using O=/tmp/build/perf),
we end up with:
$ ls -la /tmp/build/perf/feature/test-eventfd*
-rwxrwxr-x. 1 acme acme 8176 Nov 21 15:58 /tmp/build/perf/feature/test-eventfd.bin
-rw-rw-r--. 1 acme acme 588 Nov 21 15:58 /tmp/build/perf/feature/test-eventfd.d
-rw-rw-r--. 1 acme acme 0 Nov 21 15:58 /tmp/build/perf/feature/test-eventfd.make.output
$ ldd /tmp/build/perf/feature/test-eventfd.bin
linux-vdso.so.1 (0x00007fff3bf3f000)
libc.so.6 => /lib64/libc.so.6 (0x00007fa984061000)
/lib64/ld-linux-x86-64.so.2 (0x00007fa984417000)
$ grep eventfd -A 2 -B 2 /tmp/build/perf/FEATURE-DUMP
feature-dwarf=1
feature-dwarf_getlocations=1
feature-eventfd=1
feature-fortify-source=1
feature-sync-compare-and-swap=1
$
The main thing here is that in the end we'll have -DHAVE_EVENTFD in
CFLAGS, and then the 'perf bench' entry needing that API can be
selectively pruned.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-wkeldwob7dpx6jvtuzl8164k@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/build/Makefile.feature')
| -rw-r--r-- | tools/build/Makefile.feature | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature index d74bb9414d7c..8a123834a2a3 100644 --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -31,6 +31,7 @@ FEATURE_TESTS_BASIC := \ backtrace \ dwarf \ dwarf_getlocations \ + eventfd \ fortify-source \ sync-compare-and-swap \ get_current_dir_name \ |