On Tue, Nov 10, 2015 at 10:05:48AM +0000, Will Deacon wrote: > Hi Heiko, > > On Tue, Nov 10, 2015 at 08:41:24AM +0100, Heiko Carstens wrote: > > On Fri, Nov 06, 2015 at 04:21:10PM +0000, Will Deacon wrote: > > > On Sat, Nov 07, 2015 at 12:11:16AM +0800, yalin wang wrote: > > > > i just enable it on ARM64, > > > > and it can work, > > > > i don’t see some special requirement to enable this config . > > > > > > Right, so why does HAVE_LATENCYTOP_SUPPORT exist? [...] > > And looking through the kernel there is at least avr32 which would break > > at build time if the config option would be removed completely. > > > > So.. renaming it to STACKTRACE_TSK_SUPPORT would be a good idea. > > ftrace has a similar issue and solves it by having architectures define > a `config STACKTRACE_SUPPORT' symbol. Over in kernel/trace/Kconfig, > there's a `select STACKTRACE if STACKTRACE_SUPPORT', which means > that kernel/stacktrace.c gets built and a dummy (weak symbol) version of > save_stack_trace_tsk appears.
Ah, I wasn't aware of the weak symbol. > I don't think adding another STACKTRACE-related Kconfig option is > necessarily the best thing to do. Maybe we should instead have LATENCYTOP > depend on STACKTRACE_SUPPORT (already the case) and select STACKTRACE? LATENCYTOP also already selects STACKTRACE. So it looks like HAVE_LATENCYTOP_SUPPORT could simply be removed. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
