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Arnaldo Carvalho de Melo
11c6cbe706
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 <[email protected]> Cc: Andrew Morton <[email protected]> Cc: David Ahern <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Jason Baron <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Wang Nan <[email protected]> Link: https://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
10 lines
195 B
C
10 lines
195 B
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2018, Red Hat Inc, Arnaldo Carvalho de Melo <[email protected]>
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#include <sys/eventfd.h>
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int main(void)
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{
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return eventfd(0, EFD_NONBLOCK);
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}
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