From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12033 invoked by alias); 18 Nov 2013 19:15:25 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 11987 invoked by uid 48); 18 Nov 2013 19:15:20 -0000 From: "luto at mit dot edu" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/59177] steady_clock::now() and system_clock::now do not use the vdso (and are therefore very slow) Date: Mon, 18 Nov 2013 19:15:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Version: 4.9.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: luto at mit dot edu X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-11/txt/msg01710.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59177 --- Comment #3 from Andy Lutomirski --- I can't get gcc trunk to build right now, but I just distcleaned and rebuilt the 4.8 branch truck on Fedora 19, which has glibc-2.17-19.fc19.x86_64. It defines _GLIBCXX_USE_CLOCK_GETTIME_SYSCALL. This happens because: configure:19349: checking for clock_gettime, nanosleep and sched_yield configure:19378: result: no I think that the underlying problem is that --enable-libstdcxx-time defaults to "no". Shouldn't it default to "yes" (and hence run the fancy configure checks)? Configuring with ./configure --enable-libstdcxx-time does the right thing.