On Wed, 26 Aug 2026 13:28:42 +0200 Ricardo Ribalda <[email protected]> wrote:
> Hi David > > On Wed, 26 Aug 2026 at 11:55, David Laight <[email protected]> > wrote: > > > > On Tue, 25 Aug 2026 20:02:10 +0000 > > Ricardo Ribalda <[email protected]> wrote: > > > > > > diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h > > > index 44c07a66edff..80276cedda80 100644 > > > --- a/include/linux/rcupdate.h > > > +++ b/include/linux/rcupdate.h > > > @@ -488,7 +488,7 @@ static __always_inline bool > > > lockdep_assert_rcu_helper(bool c, const struct __ctx > > > context_unsafe( > > > \ > > > typeof(*p) *local = (typeof(*p) *__force)(p); \ > > > rcu_check_sparse(p, __rcu); \ > > > - ((typeof(*p) __force __kernel *)(local)) \ > > > + ((TYPEOF_UNQUAL(*p) __force __kernel *)(local)) \ > > > > Ugg... TYPEOF_UNQUAL() is absolutely horrid... > > When __CHECKER__ is undefined the whole thing is just (p). > > About using __CHECKER__: Are you suggesting using #ifdef __CHECKER__ > to use TYPEOF_UNQUAL or the current code? > > I am open to doing that, but I would like to hear from Paul if he > favors adding the (also horrid) #ifdef to save some CPU cycles on > older compilers. > > > > > I suspect reducing all the definitions would measurably improve > > kernel compile time (even before these changes). > > When I checked earlier in the other patch in this patchset, with my > compiler I can hardly see any difference in compilation times [1]. > This is probably because GCC15 direclty maps TYPEOF_UNQUAL to the > built-in __typeof_unqual__. I was thinking of the _Generic() version. But here you only want to remove the (I think) __user marker. I don't think you want to get rid of 'const'. So you don't really want gcc to remove any qualifiers. There is an similar(ish) issue when an __force cast is used to remove one of the extra qualifiers. You really want the compiler to ignore the cast - so it checks the actual types match. David > > > Thanks! > > > [1] > https://lore.kernel.org/all/canidscsmrulsrgqg76x28grxlg+hskfwhha14zcn8hdm4ky...@mail.gmail.com/ > > > > > David
