Hi all, In v5 there are few fixes suggested by Sam Ravnborg:
- Use 8 spaces for indentation in Makefile; - Rename ARCH_HAS_NORMAL_FRAME_POINTERS to HAVE_NORMAL_FRAME_POINTER; Thanks, --- Preface for those who don't know or forgot what the problem is: Gcc frame pointers do nothing useful on PowerPC (they're harmful, actually), and thus lib/Kconfig.debug makes CONFIG_FRAME_POINTER unselectable on PPC targets, but CALLER_ADDR macros are available only with CONFIG_FRAME_POINTER, therefore tracing is completely useless on PowerPC: [...] <idle>-0 0X.h3 2us+: 0:140:R + [000] 1733:120:S mvtsd <idle>-0 0X.h3 9us+: 0 (0) <idle>-0 0X..3 72us : 0 (0) <idle>-0 0X..3 73us : 0:140:R ==> [000] 1733:120:R mvtsd While it should look like this: [...] <idle>-0 0X.h3 2us+: 0:140:R + [000] 1740:120:S mvtsd <idle>-0 0X.h3 9us+: hrtimer_wakeup (__run_hrtimer) <idle>-0 0X..3 87us : cpu_idle (__got2_end) <idle>-0 0X..3 89us : 0:140:R ==> [000] 1740:120:R mvtsd I've tried to fix the issue via expanding the #ifdef in the ftrace.h: http://lkml.org/lkml/2009/1/31/141 Then Steven Rostedt suggested to implement something more generic, i.e. HAVE_NORMAL_FRAME_POINTERS Kconfig symbol. I found a way to solve the problem w/o additional symbols, but with some Makefile magic (http://lkml.org/lkml/2009/2/4/273). But because of top-level Makefile issues on other arches (http://lkml.org/lkml/2009/2/14/89) I had to abandon the approach. So, this patch set combines Steven Rostedt's idea and a small Makefile change, so that now only top-level Makefile has to know about the new symbol, and the rest of the kernel can stay with using CONFIG_FRAME_POINTER. I'm aware of commit c79a61f55773d2519fd0525bf58385f7d20752d3 Author: Uwe Kleine-Koenig <u.kleine-koe...@pengutronix.de> Date: Fri Feb 27 21:30:03 2009 +0100 tracing: make CALLER_ADDRx overwriteable But I think the patch set is still applicable, considering that it removes gcc bug workaround in a nice way, and makes CONFIG_FRAME_POINTER available on PowerPC, thus other code can rely on that. If not, I can just fill-in the asm/ftrace.h for PowerPC. -- Anton Vorontsov email: cbouatmai...@gmail.com irc://irc.freenode.net/bd2 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev