From mboxrd@z Thu Jan 1 00:00:00 1970 From: Helge Deller Subject: FUNCTION_TRACER and parisc kernel Date: Sat, 07 Feb 2009 02:19:04 +0100 Message-ID: <498CE188.60308@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: Carlos O'Donell , John David Anglin , linux-parisc Return-path: List-ID: List-Id: linux-parisc.vger.kernel.org Hi Carlos, Dave & parisc-linux mailing list, I just started looking into implementing function tracer functionality into the parisc kernel (http://cateee.net/lkddb/web-lkddb/FUNCTION_TRACER.html). While doing so, I noticed that gcc issues lots of warnings like this one: CC arch/parisc/lib/iomap.o cc1: warning: -ffunction-sections disabled; it makes profiling impossible So it seems that this statement in arch/parisc/Makefile: # Without this, "ld -r" results in .text sections that are too big # (> 0x40000) for branches to reach stubs. cflags-y += -ffunction-sections breaks with the -pg compile option which is needed for function tracing. Some searching with google brought up this thread: http://gcc.gnu.org/ml/gcc-help/2008-11/msg00128.html and esp. this answer: http://gcc.gnu.org/ml/gcc-help/2008-11/msg00141.html Or this thread: http://osdir.com/ml/linux.debian.ports.hppa/2005-06/msg00045.html Since it's late I felt too tired to look deeply into glibc and gcc myself and just thought I should ask here: Do you see any chance that -pg and -ffunction-sections could work together on hppa/linux? Helge PS: I assume my latest patches to fix loading of xfs modules only worked because we compile the kernel with -ffunction-sections by default. Disabling -ffunction-sections will then probably bring back the module loading bug... :-(