From patchwork Mon Mar 22 12:28:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 406649 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-24.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0294EC433E3 for ; Mon, 22 Mar 2021 12:50:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE67161A20 for ; Mon, 22 Mar 2021 12:50:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229944AbhCVMuF (ORCPT ); Mon, 22 Mar 2021 08:50:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:40964 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232842AbhCVMsS (ORCPT ); Mon, 22 Mar 2021 08:48:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B96D3619F0; Mon, 22 Mar 2021 12:44:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1616417075; bh=UyhdMlpYSEROnKi2OAQHU3TwT3viH8lrqexKT9RRmNA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qqE5yc3Bwgurph3MO5qjzFKHJtO4tMQYQCnIUzBymzSHagI4b/UNntGwGkiukoIWV GlGAiDPhG5sXPVbCMS0VrcfwzB1X+N7VKUZMeAgSbr1MePAV5/BV/NYvs21WL2uay+ 2NT3RlIJnjksf/Xg89BlcRBnFvl4GLjumFQVJ/ps= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adrian Hunter , Andrew Morton , David Ahern , Davidlohr Bueso , Jason Baron , Jiri Olsa , Namhyung Kim , Wang Nan , Arnaldo Carvalho de Melo , Guenter Roeck Subject: [PATCH 4.19 09/43] tools build feature: Check if eventfd() is available Date: Mon, 22 Mar 2021 13:28:23 +0100 Message-Id: <20210322121920.231048707@linuxfoundation.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210322121919.936671417@linuxfoundation.org> References: <20210322121919.936671417@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Arnaldo Carvalho de Melo commit 11c6cbe706f218a8dc7e1f962f12b3a52ddd33a9 upstream. 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 Cc: Andrew Morton Cc: David Ahern Cc: Davidlohr Bueso Cc: Jason Baron Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-wkeldwob7dpx6jvtuzl8164k@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- tools/build/Makefile.feature | 1 + tools/build/feature/Makefile | 4 ++++ tools/build/feature/test-all.c | 5 +++++ tools/build/feature/test-eventfd.c | 9 +++++++++ tools/perf/Makefile.config | 5 ++++- 5 files changed, 23 insertions(+), 1 deletion(-) create mode 100644 tools/build/feature/test-eventfd.c --- 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 \ --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -5,6 +5,7 @@ FILES= test-bionic.bin \ test-dwarf.bin \ test-dwarf_getlocations.bin \ + test-eventfd.bin \ test-fortify-source.bin \ test-sync-compare-and-swap.bin \ test-get_current_dir_name.bin \ @@ -100,6 +101,9 @@ $(OUTPUT)test-bionic.bin: $(OUTPUT)test-libelf.bin: $(BUILD) -lelf +$(OUTPUT)test-eventfd.bin: + $(BUILD) + $(OUTPUT)test-get_current_dir_name.bin: $(BUILD) --- a/tools/build/feature/test-all.c +++ b/tools/build/feature/test-all.c @@ -50,6 +50,10 @@ # include "test-dwarf_getlocations.c" #undef main +#define main main_test_eventfd +# include "test-eventfd.c" +#undef main + #define main main_test_libelf_getphdrnum # include "test-libelf-getphdrnum.c" #undef main @@ -182,6 +186,7 @@ int main(int argc, char *argv[]) main_test_glibc(); main_test_dwarf(); main_test_dwarf_getlocations(); + main_test_eventfd(); main_test_libelf_getphdrnum(); main_test_libelf_gelf_getnote(); main_test_libelf_getshdrstrndx(); --- /dev/null +++ b/tools/build/feature/test-eventfd.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2018, Red Hat Inc, Arnaldo Carvalho de Melo + +#include + +int main(void) +{ + return eventfd(0, EFD_NONBLOCK); +} --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -310,11 +310,14 @@ ifndef NO_BIONIC endif endif +ifeq ($(feature-eventfd), 1) + CFLAGS += -DHAVE_EVENTFD +endif + ifeq ($(feature-get_current_dir_name), 1) CFLAGS += -DHAVE_GET_CURRENT_DIR_NAME endif - ifdef NO_LIBELF NO_DWARF := 1 NO_DEMANGLE := 1