Messages in this thread | | | From | Arnd Bergmann <> | Date | Thu, 1 Jul 2021 15:47:48 +0200 | Subject | Re: [PATCH] sched: Use WARN_ON |
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On Thu, Jul 1, 2021 at 2:57 PM Christophe Leroy <christophe.leroy@csgroup.eu> wrote: > Le 01/07/2021 à 14:50, Jason Wang a écrit : > > The BUG_ON macro simplifies the if condition followed by BUG, but it > > will lead to the kernel crashing. Therefore, we can try using WARN_ON > > instead of if condition followed by BUG. > > But are you sure it is ok to continue if spu_acquire(ctx) returned false ? > Shouldn't there be at least for fallback handling ? > > Something like: > > if (WARN_ON(spu_acquire(ctx))) > return;
I think you get a crash in either case:
- with the existing BUG_ON() there is an immediate backtrace and it stops there - with WARN_ON() and continuing, you operate on a context that is not valid - with the 'return', you get an endless loop, as it keeps calling spusched_tick() without sleeping.
Out of those options, the existing BUG_ON() seems best.
Arnd
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