Hi Paul During the research, I found a already existing tool to detect undefined Kconfig macro: scripts/checkkconfigsymbols.py. It is marvellous! By invoking ./scripts/checkkconfigsymbols.py > /tmp/log, I found following possibly undefined Kconfig macros which may need our attention: PREEMPT_LOCK Referencing files: include/linux/lockdep_types.h PREEMT_DYNAMIC Referencing files: kernel/entry/common.c TREE_PREEMPT_RCU Referencing files: arch/sh/configs/sdk7786_defconfig RCU_CPU_STALL_INFO Referencing files: arch/xtensa/configs/nommu_kc705_defconfig RCU_NOCB_CPU_ALL Referencing files: Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst RCU_TORTURE_TESTS Referencing files: kernel/rcu/rcutorture.c and finally the macro which drive me to do this research TASKS_RCU_TRACE Referencing files: include/linux/rcupdate.h, kernel/rcu/tree_plugin.h On Fri, Jul 16, 2021 at 2:09 AM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > On Thu, Jul 15, 2021 at 04:45:04PM +0800, Zhouyi Zhou wrote: > > On Thu, Jul 15, 2021 at 11:51 AM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > > > > > On Wed, Jul 14, 2021 at 12:44:36PM +0800, Zhouyi Zhou wrote: > > > > On Tue, Jul 13, 2021 at 11:19 PM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > > > > > > > > > On Tue, Jul 13, 2021 at 06:18:12AM -0700, Paul E. McKenney wrote: > > > > > > On Tue, Jul 13, 2021 at 09:09:04AM -0400, Mathieu Desnoyers wrote: > > > > > > > ----- On Jul 13, 2021, at 12:16 AM, paulmck paulmck@xxxxxxxxxx wrote: > > > > > > > > > > > > > > > On Tue, Jul 13, 2021 at 08:56:45AM +0800, zhouzhouyi@xxxxxxxxx wrote: > > > > > > > >> From: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx> > > > > > > > >> > > > > > > > >> Hi Paul, > > > > > > > >> > > > > > > > >> During my studying of RCU, I did a grep in the kernel source tree. > > > > > > > >> I found there are 3 places where the macro name CONFIG_TASKS_RCU_TRACE > > > > > > > >> should be CONFIG_TASKS_TRACE_RCU instead. > > > > > > > >> > > > > > > > >> Without memory fencing, the idle/userspace task inspection may not > > > > > > > >> be so accurate. > > > > > > > >> > > > > > > > >> Thanks for your constant encouragement for my studying. > > > > > > > >> > > > > > > > >> Best Wishes > > > > > > > >> Zhouyi > > > > > > > >> > > > > > > > >> Signed-off-by: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx> > > > > > > > > > > > > > > > > Good eyes, and those could cause real bugs, so thank you! > > > > > > > > > > > > > > Hi Paul, > > > > > > > > > > > > > > This makes me wonder: what is missing testing-wise in rcutorture to > > > > > > > catch those issues with testing before they reach mainline ? > > > > > > > > > > > > My guess: Running on weakly ordered architectures. ;-) > > > > > > > > > > And another guess: A tool that identifies use of Kconfig options > > > > > that are not defined in any Kconfig* file. > > > > Based on Paul's second guess ;-), I did a small research, and I think > > > > the best answer is to modify scripts/checkpatch.pl. We modify checkpatch.pl > > > > to identify use of Kconfig options that are not defined in any Kconfig* file. > > > > > > > > As I am a C/C++ programmer, I would be glad to take some time to learn > > > > perl (checkpatch is implented in perl) first if no other volunteer is > > > > about to do it ;-) > > > > > > I haven't heard anyone else volunteer. ;-) > > > > > > Others might have opinions on where best to implement these checks, > > > but I must confess that I have not given it much thought. > > I recklessly cc the maintainers of checkpatch.pl without your > > permission to see others' opion, > > and I begin to study perl at the same time, after all, learning > > something is always good ;-) > > Works for me! > > Thanx, Paul Best Wishes Zhouyi
