On Wed, 26 Oct 2016 10:37:01 +0000 "Koehrer Mathias (ETAS/ESW5)" <mathias.koehrer@xxxxxxxx> wrote: > Hi Steven, > > > Or to build 3.18.43-rt46 directly, the following patches should be applied: > > > > http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.18.tar.xz > > http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.18.43.xz > > http://www.kernel.org/pub/linux/kernel/projects/rt/3.18/patch-3.18.43-rt46.patch.xz > I am using the patches as proposed. > > However with this version I get lots of compiler warnings: > > ./arch/x86/include/asm/preempt.h:118:6: warning: 'tmp' may be used uninitialized in this function [-Wmaybe-uninitialized] > tmp &= ~PREEMPT_NEED_RESCHED; > ^ > ./arch/x86/include/asm/preempt.h:112:6: note: 'tmp' was declared here > u32 tmp; > ^ > > The relevant code is the following: > > /* > * Returns true when we need to resched and can (barring IRQ state). > */ > static __always_inline bool should_resched(void) > { > #ifdef CONFIG_PREEMPT_LAZY > u32 tmp; > > if (!raw_cpu_read_4(__preempt_count)) > return true; > > /* preempt count == 0 ? */ > tmp &= ~PREEMPT_NEED_RESCHED; > if (tmp) > return false; > if (current_thread_info()->preempt_lazy_count) > return false; > return test_thread_flag(TIF_NEED_RESCHED_LAZY); > #else > return unlikely(!raw_cpu_read_4(__preempt_count)); > #endif > } > > And within this code tmp is actually not initialized, the warning is fine. > This code is new with the patch-3.18.43-rt46.patch.xz. > With the previous patch-3.18.42-rt44.patch.xz the code of should_resched > was differently (much more compact) and did not show the warnings. Thanks for the report. I'm just finishing up the stable pull of 3.18-rt, and after that, I'll be pulling in fixes for things like this. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
