Here is an example we found recently: https://github.com/apache/nuttx/pull/9002/files it's always wrong to use shced_lock as lock to protect the shared resource like this. Here is an issue which list all fixed done before: https://github.com/apache/nuttx/issues/3600 Since it's very hard to reproduce and fix this type of timing issue, we need to review all places which call sched lock/unlock and fix the wrong usage.
The suggestion: 1. disable the userspace program call sched_lock/unlock 2. but kernel can still call sched_lock/unlock Since sched_lock/unlock is hard to use correctly if the caller doesn't understand how the scheduler works. I agree with Greg that it's better to forbid the usage sched_lock/unlock in userspace. But, it's fine to keep it as before if you prefer to keep the freedom. Let's focus on the first two item: 1. Add sched_lock()'s ability to the enter_critical_section() 2. Correct the incorrect usage of sched_lock step by step Thanks On Sun, Apr 23, 2023 at 7:54 PM Fotis Panagiotopoulos <f.j.pa...@gmail.com> wrote: > Hello, just a recommendation. > > If something is prone to missuse by the users, don't remove it. > > Rather: > * Document clearly it's quirks. > * Provide checks and assertions catching the missuse. > > > On Sun, Apr 23, 2023, 14:49 Sebastien Lorquet <sebast...@lorquet.fr> > wrote: > > > Hello, > > > > I have a similar feeling about this. > > > > Remember, if it isn't broken, dont fix it. > > > > Sebastien > > > > > > On 4/23/23 13:32, Tomek CEDRO wrote: > > > hey there Yun, i am also strongly against removing working code that > had > > > been here for a long time has been carefully designed gives granular > > > control etc. > > > > > > understanding of the code and possible misuse is up to developer. > > > > > > maybe the problem needs better explanation and discussion which is > always > > > good. > > > > > > but removing basic building blocks that work and already have strong > > > dependencies is not how things are done in unix world. in fact this is > > the > > > kind of approach that destroys modern world (and the ict technologies). > > it > > > is impossible to build anything with no solid fundaments that > constantly > > > change. progress is about systematic development, step by step, on what > > is > > > already here, not by enforcing changes and removing things that work, > > > evolution not revolution. > > > > > > have a good day :-) > > > > > > -- > > > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info > > > > > >
